wall insulation

dfader

Hi,
I am looking for some advice for wall insulation for a new build. Its a 2500sq ft house. Using block cavity wall construction.

I am planning on insulating as follows from outside to inside:

100mm block
100mm cavity with 80mm xtraterm or similar high density insulation
100mm block
60mm xtraterm between battens.
38mm cozy board liner.

Is this the best way to insulate a cavity block wall. I intend using this method as i can do the insulating work insde myself rather than paying for a contractor to do external insulation

My concerns are:

Cold bridging from precast concrete first floor, cold bridging in general

Interstatial condensation

Not being as good as external insulation because there is no thermal store in the walls to re-radiate stored heat gained through solar gain from glazing

Helpful advice grately appreciated

beyondpassive

Consider 220mm EPS silver bead filled masonery wide cavity with careful detailing of ground detail, eaves and window reveals. You could use 150 quinlite on inner leaf and their foundation block on the internal side of the rising wall to reduce cold bridge at floor. Dry lining isn't suitable if your precast only has the 80 foil faced phoenic outside it. You can use cosy board on the north and east elevations to raise the surface temp, however with penetrations for plumbing and electrical services, the effectivness of the lining will be reduced.

The performance of the phoenic insulation boards is substantially reduced due to the manner of fitting and the extent of cold bridges at junctions, this means the inner leaf can become cold and warm moisture laden air can condense on it inside the dry lining. Put most of you insulation in one plane and maintain continuity of insulation and air barrier. good luck.

tred

dfader wrote: »

Hi,
I am looking for some advice for wall insulation for a new build. Its a 2500sq ft house. Using block cavity wall construction.

I am planning on insulating as follows from outside to inside:

100mm block
100mm cavity with 80mm xtraterm or similar high density insulation
100mm block
60mm xtraterm between battens.
38mm cozy board liner.

Is this the best way to insulate a cavity block wall. I intend using this method as i can do the insulating work insde myself rather than paying for a contractor to do external insulation

My concerns are:

Cold bridging from precast concrete first floor, cold bridging in general

Interstatial condensation

Not being as good as external insulation because there is no thermal store in the walls to re-radiate stored heat gained through solar gain from glazing

Helpful advice grately appreciated

I am in a similar situation, I Am considering a 150 mill cavity, with a 140mill aerobord platinum insulation. WAs looking a lot at the beaded solution, but there seems to be pros and cons out there about them...wiht my implementation I am leaving a ten mill space for air circulation....

sydthebeat

tred wrote: »

I am in a similar situation, I Am considering a 150 mill cavity, with a 140mill aerobord platinum insulation. WAs looking a lot at the beaded solution, but there seems to be pros and cons out there about them...wiht my implementation I am leaving a ten mill space for air circulation....

using full fill board insulation still leaves the risk of thermal looping.

I have yet to see a house properly blocked that didnt have mortar snots or proud mortar courses which didnt keep the board from the wall. Its very easy for a board to be pushed 10mm out from an inner leaf due to improper coursing.

tred

sydthebeat wrote: »

using full fill board insulation still leaves the risk of thermal looping.

I have yet to see a house properly blocked that didnt have mortar snots or proud mortar courses which didnt keep the board from the wall. Its very easy for a board to be pushed 10mm out from an inner leaf due to improper coursing.

I hear ya Syd. And Both sides argue a different con. My concern is moisture moving from outside to inside. I am selectivley picking blocklayers on quality over price and understanding of insulation. Again, I havent made my mind up 100 percent yet..This country has more of a moisture issue over cold if u ask me!!...

moan 77

i have same problem. i went with 100mm standard block inner leat 100mm HD insulation 50mm cavity 100mm standard block outer leaf, keep eye on blocklayer, keep talking about heat leak and so on.:D

:mad::mad::mad: hey this perimiter edge insulation keep hearing 25mm why only 25mm we keep hearing 100 mm in floor is now not enough and looking for more in walls to so why only 25 mm im the floor dont match up.:mad: :mad::mad:

dfader

beyondpassive wrote: »

Consider 220mm EPS silver bead filled masonery wide cavity
QUOTE]

Thanks for advice.

Do you mean the actual cavity is 220m. thats a very wide cavity. Wouldnt the blocks would need to be on the flat on inner leaf, adding to expense.

it makes cense to use lower density blocks on the inner leaf. would be concerned about the cost of them though. I am hoping to hit a U value of 0.15 for minimum expense.

moan 77

The cavity is 150mm that between the inner and outer leafs, each leaf 100mm so wall depth 350. Got any idea why most people quote 25 mm perimiter edge insulation and not something bigger, we are now told to over insulate in floor up to depth of 300mm in some cases ( too late for me i have only 100mm) so why not 50mm or 70mm perimiter insulation, this one has me quzzled.

beyondpassive

220mm full fill loose bead fill with vartry eng type wall ties, rising wall needs to be designed to minimise cold bridge, after all the inner leaf sits on the cold block rising wall, 25mm of perimeter insulation is like an ash tray on a motorbike, stone useless. Putting AAC blocks on the dry side of the rising wall and the first one or 2 tiers of inner leaf block will help reduce the heat loss from the floor here.

If you hit 0.15 in your wall, you need to make sure that where your planer elements meet the same level of insulation is maintained give or take 10-15% otherwise this cold bridge will result in a surface temperature below dew point. This is why now we are starting to see mould growth on window reveals in the least heated bedrooms in post 2002 regs houses. Get the rising wall junction and eaves junction as close to the wall and roof level of insulation. Theres a point of diminishing returns in insulating in planer elements like walls and roofs, with masonery this is about 0.175 so put the effort into improving the junctions.

justflow1983

Can I just be devil's advocate and ask if you've considered timber frame? You can get a lot more insulation into the timber frame and your wall assembly will end up being thinner and performing better. If you're self building you can order the frames and do the rest yourself.

Timber frame houses on the continent and in North America last for hundreds of years, its no less durable than block and has the advantage of being much easier to make changes to later. If properly detailed, they also retain less mouisture than block and stay very dry.

dfader

Thanks for your help guys, did some calculations, attached;

Leaning towards the wide filled cavity but concerned about structural stability.
Will the inner wall need to be block on the flat?

beyondpassive

depends on: single storey or two? distance from corner, self weight of suspended slabs, type and spacing of wall ties, footing type.

200 cavity has been done 2 storey with

Calcs look good, some observations.
Calc 1
Lamda of 0.023 for Polyiso is a overstates the performance, Its 0.23 when it comes hot off the production line. Also as the cavity has weep holes, it is an open vented cavity, therefore contribution of the outer leaf and air gap is reduced. Inner liner needs to be continuous at window eaves and at suspended floor and roof joists. 0.142 U- Value is wildly optomistic, 0.2 would be more accurate.
Calc 2.
Insulation would be nearer 0.037 for EPS bead, you could use 150mm quinlite inside and use the lamda of 0.17

Calc 3. I'm getting 0.157 U-Value for the 220 wide full fill eps cavity.


Next step Psi value thermal bridge calculations.

vartry eng ties.jpg

dfader

Thanks bp,
I should have clarified, its a two story house. Is a 200mm cavity structurally sound for two story?

beyondpassive

Thats a matter for your Str. Eng to verify, if he can check the figures through calcs all the better. lateral loading seems to be the concer, but this is dealt with through using special stainless steel wall ties, each one a little cold bridge, but very stiff. In most cases 100-200cav-100 is right, in other cases 150 quinnlite inner leaf might be required.

soldsold

I tried to cut one of these wallties today as it was an excess walltie that was not needed. I tried cutting it with a bolt cutter - no chance. its a very strong material.

soldsold

Agreed on the structural concerns not being a major issue, 300mm cavities in the UK have been shown to work ok. bear in mind that 200mm wallties need 450x450 centers and a walltie at every course around windows and doors - so its not exatly skimping on structural support. Having said that, my blocklayers found it a lot easier to push in the wallties afterwards rather than building them into the mortar course, so they were building in bridges without adding full structural strength. 95% of the ties seemed locked in tightly once the mortar set but the 5% the were loose bugged me.

Also the blocklayers were messy with mortar snots and the wall ties got a good coating that needed a bit of time to clean the ties. other than that, building 200mm cavities went very smoothly.

dfader

Thanks lads for your help and bp for looking over my calculations.

I am now looking at using 150mm quinn lite inner and 100mm PIR in a 150mm cavity, 100mm dense block outer, with the possibility of later pumping the remainder of the cavity, my calcs attached.

My reasoning being;

If i use a 150mm cavity i can save by using standard wall ties, i hear wide cavity wall ties can be expensive.

With the 150mm cavity i wont need to worry about locating suitable cills.

If i pump the cavity after i will eliminate thermal looping.

Also, I know a tidy blocklayer;).

What you think?

ps: I would like to research the block route first just flow, thanks for your sujestion

beyondpassive

Dfader,

If you are going down the PIR route with 150 cavity, you could consider this system.

1. Build 150mm inner leaf with wall ties.
2. Apply 100PIR to a 120mm cavity (or an 80mm and 60 mm PIR with foil facing out, staggered joints to a 150mm cavity)
3. Tape all joints, corners and wall ties, construct roof install windows.
4. Air test and thermography to walls, make repairs.
5. Build outer leaf.

manufacturers claims than PIR has a conductivity of 0.023 are very dubious, safer to assume about 0.027.

The above system is very labour intensive, better to go wide cavity at the end of the day.

dfader

beyondpassive wrote: »

Dfader,

If you are going down the PIR route with 150 cavity, you could consider this system.

1. Build 150mm inner leaf with wall ties.
2. Apply 100PIR to a 120mm cavity (or an 80mm and 60 mm PIR with foil facing out, staggered joints to a 150mm cavity)
3. Tape all joints, corners and wall ties, construct roof install windows.
4. Air test and thermography to walls, make repairs.
5. Build outer leaf.

manufacturers claims than PIR has a conductivity of 0.023 are very dubious, safer to assume about 0.027.

The above system is very labour intensive, better to go wide cavity at the end of the day.

Thanks BP,
The method you propose is very labour intensive and not really an option for me a self builder. Do you not think that filling the remainder of the cavity will help ensure airtightness?
If i did go with the with cavity full of Beads my calculations tell me that 200mm and not 220mm will be sufficient. thereby allowing me to use these wall ties (http://www.qwikfixings.com/why-gfrp-wall-ties.aspx). I know that taking a thermal conductivity of 0.037 for the beed is more prudent. These wall ties are good up to 200mm.

beyondpassive

Ya non metalic wall ties are worth considering, The Teplo wall tie has just gotten BBa cert for 300mm Cavities. http://magmatech.co.uk/index.php?option=com_content&task=view&id=14&Itemid=27

Mr Fader, might be worth parking the cavity insulation for now and concentrating on cold bridges, when building masonery, heat loss at floor and eaves junctions and around openings should be detailed up and investigated through the free Therm software.

sydthebeat

dfader wrote: »

Thanks lads for your help and bp for looking over my calculations.

I am now looking at using 150mm quinn lite inner and 100mm PIR in a 150mm cavity, 100mm dense block outer, with the possibility of later pumping the remainder of the cavity, my calcs attached.

My reasoning being;

If i use a 150mm cavity i can save by using standard wall ties, i hear wide cavity wall ties can be expensive.

With the 150mm cavity i wont need to worry about locating suitable cills.

If i pump the cavity after i will eliminate thermal looping.

Also, I know a tidy blocklayer;).

What you think?

ps: I would like to research the block route first just flow, thanks for your sujestion

dfader,

that u value calculation does not take into account thermal bridges such as wall ties in the cavity and mortar joints in the aac block (if used)

these will make a significant difference to teh resultant factor and should be inputted.

unless of course you are going to use the thin bed mortar system and wall ties which have low conductivity. But of course, there is knock on effects for these.

dfader

Thanks syd,
I've calculated in the bridged layer, attached. Got a u value of 0.18. starting to think that this method of construction is not viable. maybe timber frame is the way to go

justflow1983

I grew up in the states, and its made me a very big timber frame fan. Its just such an elegant way to build.

If you'd like to stick with masonry-type construction, you can look at poroton or thermoplan blocks. They are basically the same thing, its a terracotta block with lots of gaps in them. You don't need to leave a cavity because they are very vapour-open, the proprietary render is fixed directly to them. You would insulate further internally with this system.

In a meeting today our supplier on one job gave us a K-value of 0.11 W/mK for them.

justflow1983

dfader wrote: »

Not being as good as external insulation because there is no thermal store in the walls to re-radiate stored heat gained through solar gain from glazing

Just re-read this. Most solar heat gain will be stored in the floor in front of the window. Unless you have a wall directly in front of a window, known as a trombe wall, you can get solar gain by having a concrete floor slab or even tile in front of windows.

dfader

Found a mistake in that last u value calculation:eek:. hope i got it right this time. Revised calculation attached, giving a more favourable u value for wall. Still interested in this wall build up. Will try the therm software as sugested BP and need to do the Psi calculations. I am concerned about thermal bridging around opes, at the floor/wall junction and at the eaves. I would like to do a full cost comparison between this, external insulation and timber frame. I persume a 500mm wide wall means wider and deeper foundations.


BP you seem to be experienced in this type of construction. Would like to see construction details for the above mentioned junctions. eg. do you use a slate cavity closer instead of the block cavity closer?, that kind of thing.

thanks,

sydthebeat

dfader wrote: »

Found a mistake in that last u value calculation:eek:. hope i got it right this time. Revised calculation attached, giving a more favourable u value for wall. Still interested in this wall build up. Will try the therm software as sugested BP and need to do the Psi calculations. I am concerned about thermal bridging around opes, at the floor/wall junction and at the eaves. I would like to do a full cost comparison between this, external insulation and timber frame. I persume a 500mm wide wall means wider and deeper foundations.


BP you seem to be experienced in this type of construction. Would like to see construction details for the above mentioned junctions. eg. do you use a slate cavity closer instead of the block cavity closer?, that kind of thing.

thanks,

how are you calculating thermal bridging due to wall ties???

even if you use the basalt fibre ties, you still need to include them in the calculations...

beyondpassive

dfader wrote: »

BP you seem to be experienced in this type of construction. Would like to see construction details for the above mentioned junctions. eg. do you use a slate cavity closer instead of the block cavity closer?, that kind of thing.

220-eaves.jpg

This is a detail used by a contributor to this thread. Work out the Floor Psi first, the eaves one is trickier. D'ont forget the threshold detail too.

dfader

sydthebeat wrote: »

how are you calculating thermal bridging due to wall ties???

even if you use the basalt fibre ties, you still need to include them in the calculations...

thanks syd. will try that and post it up. i did a rough calculation and my u value increased by 0.01.

dfader

beyondpassive wrote: »

220-eaves.jpg

This is a detail used by a contributor to this thread. Work out the Floor Psi first, the eaves one is trickier. D'ont forget the threshold detail too.

Thanks BP. getting that detail is a great help. It looks to me like the rafter has two birdsmouths there; one over the wallplate as normal and one over the gutex board, helping hold it down, is this right, looks like the second birdsmouth is going through over half the rafter.

beyondpassive

yes two birdsmouths, I dont generally like to be too perscriptive, ofte its worth getting the chippy's input.

Heres some photos i was kindly allowed to take at a certain forum members build.

eaves.jpg
open eaves photo.jpg

sinnerboy

BP - did you speak to the structural engineer invlolved ? - I would be very concerned about the thrust force imposed by the rafters

soldsold

Hi All,

The rafters in beyondpassives pics are 225mm deep, 26 ft long and supported by knee walls further up the roof. Its a 35 degree roof pitch and the knee walls are around 5 feet high if that helps.

The cavity has not been closed yet, but I will need to close the cavity in some form to allow bead insulation to be pumped in from below and cellulose to be pumped in from above, to keep keeping them separate from each other. I am considering either using gutex board offcuts, or stapling parpac membrane, or stuffing rolls of rockwool into the cavity, or some other method. Any advice would be welcome.

On the subject of the rafter load, my roofer spent a long time trying to convince me to use a block cavity closer, as he had the same concerns and has had seen rafters move block walls over the years. In the end he strapped the wallplate to the blocks below using long straps that go down about 4 courses and are spaced fairly close together (about every 800mm) and he is happy that this will provide enough support. My Engineer is also a structural engineer and has no problem with this. My roofer is excellent and does everything by the book and if he says its ok I trust him on that.

I am using an RSJ to support the A-roof in one section that doesnt have knee walls or concrete ground floor ceiling slabs. I also have the option of using thick steel wire straps (sorry dont know the term) half way up the rafters to stop them from spreading. This roof section is at 400mm centres for safety (because of cathedral ceilings).

150mm solid concrete ground floor ceiling slab is resting on most other exterior walls so is providing resistance to the force being provided by the rafters - how much I dont know but my engineer is happy and he is known for being conservative. The roof where the concrete slab is has rafters at 600mm centres to reduce cold bridging.

Some of the exterior walls have blocks on the flat so this cant be any different to the spec for externally insulated houses surely?

Dfader feel free to call down to look at the wall/ roof structure before it gets closed in, we are in Birr Co Offaly. PM if you want to have a look.

P.S. the bitumen sealer and expanding foam details seen on the pics are a copy of the denby dale passive house being built in UK, its a good blog to read (google will find it). The solitex wrapped around the first floor concrete slab is standard detail nowadays. Beyondpassive has been advising on the insulation/ phpp spec/ windows/ etc from the start of the build, its difficult to do the whole job without some external professional assistance and Id highly recommend getting someone on board that has experience and contacts to be able to talk to as you find details you need to answer - especially as there doesnt seem to be a precedent for some of these details as there is with most "passivehaus" projects.

Cheers,

Steve

dfader

sinnerboy wrote: »

BP - did you speak to the structural engineer invlolved ? - I would be very concerned about the thrust force imposed by the rafters

I persume in my case, ceiling joist at wallplate level bolted to rafter will prevent roof spread here.

sold sold thanks for the invite down to Birr and info, based in nortwest so might not get to avail.

soldsold

dfader wrote: »

I persume in my case, ceiling joist at wallplate level bolted to rafter will prevent roof spread here.

My 'guess' is that a truss roof would be another option to prevent the rafter spread?

dfader

soldsold wrote: »

My 'guess' is that a truss roof would be another option to prevent the rafter spread?

yes, less cold bridges too due to wider spacing of trusses

soldsold

If buying a truss roof, consider "bob tail" trusses that have an upstand at the eaves which will allow more insulation depth where the eaves meet the cavity wall

sinnerboy

Solssold can you ask your engineer ( or if you know anyway yourself )

1. what type of wall tie are you using
   
2. what tie spacings - horizontal / vertical
   
3. what ties spacings vertically at openings
   
4. any increase in ties at the top at the wall to compensate for no structural closing of the wall ( i.e. the bridging block course your blocky spoke of )
   
5. how are you closing your jambs
   
6. how are your window cills rested - i.e. do they cross the cavity to bear on the internal leaf ?

dfader

beyondpassive wrote: »

220-eaves.jpg

This is a detail used by a contributor to this thread. Work out the Floor Psi first, the eaves one is trickier. D'ont forget the threshold detail too.

Had a look through part L, cant see any examples of how to calculate Psi, ia it in there.
Thinking of using plastic insulated cavity closers; will these help solve a lot of my coldbridge problems

soldsold

1 what type of wall tie are you using - Vartry Engineering 17mm wide 2.3mm thick 350mm long

2. what tie spacings - horizontal / vertical - 450 x 450mm



3. what ties spacings vertically at openings - Every block course



4. any increase in ties at the top at the wall to compensate for no structural closing of the wall ( i.e. the bridging block course your blocky spoke of ) - No



5. how are you closing your jambs - They have a zip but I usually wear boxers to bed



6. how are your window cills rested - i.e. do they cross the cavity to bear on the internal leaf ? - No they are sitting in 50mm into the cavity, the 50mm is because the sills have a 25mm lip at the back and am leaving a 25mm gap between the lip and the outer block inside edge for window fitting

Not sure how to close the cavities yet, Im thinking of wrapping wide DPC in polystyrene blocks and pushing tight into the jamb, but havent really thought of a full plan yet

sinnerboy

soldsold wrote: »

5. how are you closing your jambs - They have a zip but I usually wear boxers to bed

dfader

Thanks for the help lads,

Still unsure about my wall build up. I am keen to go with the full fill cavity to avoid thermal looping but research it has raised a few concerns for me, namely;

1. As the water percolates down through the beads is there a danger of pooling at ground level and pussible moisture penetration at ground floor level. I will be having a radon barrier so this might help, but water might still back up to above dpc level in the cavity. would it be an advantage to leave weep holes above where radon barrier exits wall.

2. When i factored in flat type wall ties and mortar joints the wall U value came to 0.16 - 0.17, (these calcs have been done on excel and not on a package and may not be fully accurate). this is stilll probably better that loss due to thermal looping using rigid boards though.

3. Getting wide cills, can standard cills be supported in the cavity.

4. Plastering quinnlite blocks.

5. Snots on wall ties creating air pockets in the beads.


Another option that ive been looking at that might help overcome some of the above is a 150mm cavity with the 140mm Aerobord with possible 100mm quinnlite and a layer of drylining inside. this gives a U value of 0.14 - 0.15. Its attractive because it comes with wall ties and seams easy to use. But Does this type of board eliminate thermal looping? If i some how sealed the top of the board with the inner face of the wall would this help?

beyondpassive

dfader wrote: »

1. As the water percolates down through the beads is there a danger of pooling at ground level and possible moisture penetration at ground floor level. I will be having a radon barrier so this might help, but water might still back up to above dpc level in the cavity. would it be an advantage to leave weep holes above where radon barrier exits wall.

2. When i factored in flat type wall ties and mortar joints the wall U value came to 0.16 - 0.17, (these calcs have been done on excel and not on a package and may not be fully accurate). this is stilll probably better that loss due to thermal looping using rigid boards though.

3. Getting wide cills, can standard cills be supported in the cavity.

4. Plastering quinnlite blocks.

5. Snots on wall ties creating air pockets in the beads.

Another option that ive been looking at that might help overcome some of the above is a 150mm cavity with the 140mm Aerobord with possible 100mm quinnlite and a layer of drylining inside. this gives a U value of 0.14 - 0.15. Its attractive because it comes with wall ties and seams easy to use. But Does this type of board eliminate thermal looping? If i some how sealed the top of the board with the inner face of the wall would this help?

I don't think you should be unduly concerned with the added heat loss from wall ties, If the wall U-value of 0.165 goes out to 0.175 that is relatively inconsequential. You need to look at the cold bridges at eaves and floor detail at this stage.

1. If your DPC's around windows and doors are detailed with basic attention to detail, your cavity will remain dry. Vapour pressure caused by heavier denser internal air will push moisture out of the cavity. This vapour pressure causes moisture to migrate to the outside surface of the wall for 11 months of the year. Its only when both the average outside temp + humidity are much higher than inside for a sustained period, such as July that vapour pressure works inwards. The beads dont offer much by way of capilary movement to moisture that may sit at the base of the cavity, it is recommended that the cavity run to 150mm min below DPC level. Water in the cavity isn't a risk.
2. You can get certified passive with walls of 0.17 if your surface area to volume ratio is low. Your roof and floor at say 0.15 and 0.14 respectively will bring up the average and sorry to sound like a broken record but the cold bridges need attention. Windows with frame U-value of >1 could then come into the equation, saving you a few bob.
3. The cill shouldnt bridge the cavity, it will just cantilever 50mm into it. Alternativly you could use EPS cills or PVC trays. The cavity can be closed with EPS block cut to fit. The windows or screens sit IN the cavity and self weight and wind loading must be supported by the inner leaf. In some cases this will necessitate steel brackets for large windows.
4. Plastering any block can be a problem if the block is not allowed to cure and then wetted to stop the capillary pull from block to plaster.
5. Stop picking your nose, blocklayers used to be instructed on keeping a clean cavity by building inner leaf first and putting cardboard over the cavity, this is a simple site supervision task.

I'm not gone on the alternative option, the dryling is comprimised at suspended floors and at elec junction boxes, additionally it reduced the thermal inertia of the walls. The 220 cavity offers a better solution, with the option of a quinnlite inner leaf of 100 + 150 and graphite (mag____ch) wall ties.

How's the Therm model coming on Mr Fader? ( or is it Miss)

soldsold

Keeping the wall ties clean just needs a long piece of slating batten and a few hours to clean the ties in one go.

If pumping the cavity the wall tie manufacturers might make ties with the flat part vertical instead of horizontal so it doesnt catch as much mortar.

Asking the blocklayers to scoop UP not DOWN when laying the blocks helps, I had one guy scraping the extra mortar straight down into the cavity every block which almost annoyed me. I decided from day 1 not to bother getting annoyed about anything that goes wrong, it makes for an easier build. Good planning and attention to detail and if that doesnt work, take the mistake on the chin and move on.

dfader

Thanks for that bp. Have not worked on the Therm software yet. Will let ye know how I get on.
As for the Mr or Miss, ill think ill keep you guessing

djlinehan

tred wrote: »

I hear ya Syd. And Both sides argue a different con. My concern is moisture moving from outside to inside. I am selectivley picking blocklayers on quality over price and understanding of insulation. Again, I havent made my mind up 100 percent yet..This country has more of a moisture issue over cold if u ask me!!...

The issue isnt moisture being drawn in its a cold spot on the internal wall which moisture will condence on. Iits all down to the masons and the wall ties.

Niamh24

How can you tell if your house has cavity wall insulation - my house is 10 years old (a bungalow) and I feel the rooms at the end of the house quite cold.
Also, I know this is a separate issue - have any of you any experience with condensation building up on pvc windows and aluminium doors - my front door is made of pvc and aluminium and every morning it is soaking wet - the floor is starting to rise and damp on one of the walls - the same for my sliding door at the back of the house
Will a front door porch solve the problem?

djlinehan

Niamh24 wrote: »

How can you tell if your house has cavity wall insulation - my house is 10 years old (a bungalow) and I feel the rooms at the end of the house quite cold.
Also, I know this is a separate issue - have any of you any experience with condensation building up on pvc windows and aluminium doors - my front door is made of pvc and aluminium and every morning it is soaking wet - the floor is starting to rise and damp on one of the walls - the same for my sliding door at the back of the house
Will a front door porch solve the problem?

Ok you have a couple of problems there that may or may not be related to each other..
where is your house...that is to say, in dublin the building regulations are slightly different (because the weather is very different to the westen half of the country)....
Now the rooms at the end of the house being cold could be the fault of the heating or insulation in the attic.
The wall insulation needless to say should be there a ten year old house is covered by the building regulations of the time which wouldnt be near as good as todays regulations but would inculde at least 50mm of areoboard in-cavity insulation or insulated plaster slabs afixed to the inside walls....
To up grade the insulation in the house can be relatively easy just putting alot more into the attic to the more expensive option of replacing windows and getting pumped in cavity insulation. there is grants available for some of these works and you can find out about them from "sei" they will point you in the right direction and recomend regestered instalers...

Now the dampness that is a mine field ...the warm air of a house is full of moisture which will condence on any thing colder than the current air (eg bottle forming drops on the outside)..
dampness generially occurs in bathrooms and kitchens due mostly to the amount of steam generated by cooking and showers but can occur any where... the solution is ventilation keep the air "fresh" open a window or any vents for at least some of the day. now i am aware that you thread started with you mentioning that the house is cold and opening windows isnt what you need to hear.
another solution would be to buy a small dehumidifier and let it run every day that would "dry" the air causing less condensation.
but fresh air is cheapest answer...

hope that helps some bit...

sydthebeat

djlinehan wrote: »

.........., in dublin the building regulations are slightly different (because the weather is very different to the westen half of the country).......

dj,

ill give you a chance to clarify that statement because on first reading its incorrect. What exactly do you mean???

Niamh,
Firstly you need to discover if your house has a cavity. If you knock on the inside of your external walls do they sound solid or hollow. If solid its safe to assume you have a cavity; if hollow you may have whats referred to as "cavity block" wall.
If your house is 10 years old it should have been built to comply with 1992 building regulations, where generally 50mm or 2" of polystyrene insulation was incorporated into the cavity. As dj has said theres grants available out there to upgrade you insulation by pumping the remainder of the cavity. Installing attic insulation should be a minimum. You probably only have about 4" of quilted material up there, you should have 300mm (or one foot) of quilted material.

The condensation is as a result of inadequate ventilation. Check to see if all you wall vents are not sealed up, check to see if your mechanical vents (xplaiers) are working properly.

djlinehan

sydthebeat wrote: »

dj,

ill give you a chance to clarify that statement because on first reading its incorrect. What exactly do you mean???

granted i didnt mean that the regulations are different for dublin because its dublin...
but in the 1997 building regulations (which would cover the relevent thread)
the greater dublin area was in wind zone "A" and having estimated gust speeds of 44m/s with a return period of 50 years
it wasnt unusual to find a house built 10 years ago in the dublin area built with cavity block .. as opposed to cavity wall..which would be relevent to the original thread question asking if there was insulation in the cavity..

so the regulations wernt different for dublin but meeting the standards did lead to different construction methods nation wide..

So my apologies

p.s. knocking on the wall will only tell you whether its timberframed , insulated slab , ordinary slab or blockwork it wont tell the type of block..

PatcyMcl

Insulationg inside the blocks is ok but you still have a thermal conduction at the masonry ribs.

The best inslation for masonry walls is styrofoam sheeting on the OUTSIDE.

carraigard

Hey guys don't mean to change the subject as such but has anyone thought/know exactly what type of material is used in those poystyrene beads that are now being used to insulate walls (of older houses). Am looking at insulating walls in existing house and wondering is a material specified as "closed cell polystyrene FRA thermal bead coated with a air drying adhesive during the injection process" ok with regards to chemical toxins etc. I would be concerned about maybe longterm fumes or chemicals could be released from those insulation products.