Cavity wall insulation

chickey

Anyone any experience of getting cavity walls in a 2nd hand house insulated? have a c.30 yr old house - which can be pretty cold - was thinking of looking in to cavity wall insulation as a means of improvement. Any got it in? does it make a good difference? what kind of price would it come at for a 3 bed semi? if anyone had any recommendations on someone doing this in Wexford better again!

Many thanks

slave1

I have a 30 yr old house too and got the cavaty walls filled a few years ago
The choices were beads/pumped liquid that solidifies into a foamy like substance

I went for the pumped and Shannon Insulations - Mullingar I think - fitted, they drilled holes every 6 feet or so at about 4 foot vertical intervals, they filled in the holes and had plently of dyes to cover the holes i.e. part of the house is white pebble dash, part grey brick - can't really see holes unless you go looking for them.

I also got the adjoinging garage pumped as the pumped stuff is the only insulation type that will work with 9" cavity blocks.

Did it make a difference?
Yes when Dad got it done in the late 70's in the family home.
I can't really say from my experience as I got uPVC windows installed/some dry lining/new heating/rads and attic insulated at same time - just bought the house.
It was fcuking freezing and now holds heat very well, 1900 sq feet kept more than comfortable with 2 buckets of coal - back boiler. I haven't had a fill of oil in 18 months and have half a tank still.

Last year I converted the garage and some of the foamy insulation popped out when I made a window opening and it was in good nick and warm to the touch

Cost about 500-700 pounds at the time I think - vague memories - for a 4 bed semi.

Phone around

KoNiT

My da got his house done about 6-7 years ago, brilliant job. He had the pumped liquid job. It definatly made a difference

pipers

came across this firm during a refurb of a house last summer.
They seemed top class

A & A Insulation
Collinstown, Mullingar
044 - 66100

Victor

You could also try drylining the inside of the walls with Gypliner or somethign similar from Gyproc / Gypsum Industries - essentially a combined plasterboard and insualtion. Best used where there is no cavity, like with pre-1960 houses. The problem is you would need to replaster adn you would loose about 50mm around the perimeter of the house.

Originally posted by slave1
Last year I converted the garage and some of the foamy insulation popped out when I made a window opening and it was in good nick and warm to the touch

All insulation is (should be!) warm to the touch.

brendan7

I got a Company called ************** to pump my walls two years ago and they also did my Fathers house which is built with 9" hollow blocks. They were fantastic, came on time when they said they would and the difference it has made to both houses is unbelievable, they used a foam which was pumped in and they also insulated the attic, i have just checked there website which is ******************
and it shows the foam being pumped into the wall.

aka_Ciaran

I have a house from 1962 that has those poxy cavity blocks. After a lot of research last year I went with dry lining on the inside...I lined all the external walls with 2 inch insulated plaster board and then tape and join.

A few people told me that pumped insulation isn't guaranteed to get into all the cavities in cavity blocks, as there could be lumps of mortar blocking some of the holes, and also I think the holes in the blocks are staggered so even if it's pumped from the top it can't get into all the gaps.

Not sure if the OP meant normal cavity walls or the older cavity blocks.

the GALL

Im livin in wexford
the neighbour got it done last year and said you could heat his house with a candel Ill be doing the same shortly
If you want the guys/company name who did it P.m me and ill send it on...and no it wasn't that expensive I think He said a grand for a 1,500 dormer but don't quote me on it.

delly

brendan7 wrote: »

I got a Company called 'We don't like to pay for advertising' to fill my house

Thank you Brendan O'Carroll, but you have to pay to advertise here. Bye bye now.

John mac

i wonder if the op has had it done yet (4 years later):D

wiredup

My house was built in the 80's and I purchased it 4 years ago. The previouse owner had had cavity insulation done in the last ten years or so. The blown in polystyrene little ball stuff.

I've always thought the house was not that warm and was convinced this cavity wall insulation was rubbish.
Anyway, just before Christmas last I had someone round to knock a new doorway through one of my external walls. It gave me a chance to inspect the cavity and sure enough my suspicions were correct.

Who ever laid the blocks when building my house left masses of mortar sticking out inside the cavity between the blocks. MR cavity insulation guy had blown in the stuff from the top (you can see the insertion holes around the the house) and the insulation hit this protruding mortar went no further.
From what I can see, less that 50% of the cavity area had insulation.

So I would advice anyone to inspect their cavity before paying for this.
And if anyone knows of a solution to fix my problem I'd be very keen to hear it.

yop

wiredup wrote: »

My house was built in the 80's and I purchased it 4 years ago. The previouse owner had had cavity insulation done in the last ten years or so. The blown in polystyrene little ball stuff.

I've always thought the house was not that warm and was convinced this cavity wall insulation was rubbish.
Anyway, just before Christmas last I had someone round to knock a new doorway through one of my external walls. It gave me a chance to inspect the cavity and sure enough my suspicions were correct.

Who ever laid the blocks when building my house left masses of mortar sticking out inside the cavity between the blocks. MR cavity insulation guy had blown in the stuff from the top (you can see the insertion holes around the the house) and the insulation hit this protruding mortar went no further.
From what I can see, less that 50% of the cavity area had insulation.

So I would advice anyone to inspect their cavity before paying for this.
And if anyone knows of a solution to fix my problem I'd be very keen to hear it.

ANy idea of how I can inspect the cavity without knocking a door through

Parents onto me today to get them quotes for blown insulation in a 50mm cavity in a house constructed in 1969.

What sort of costs are we looking at with those who have it done? Any do's and dont's

builditwell

In my experience in renovation and bring buildings up to code, the blown in insulation makes little or no difference. I have never used the said material as it doesnt give a guarantee or an estimated U value improvement. 99% of all cavity walls will be thrown up by blocklayers especially ones built 20-30-40 years ago. If I was doing it for myself i would strip internal plasterboard from the cavity walls batten it out and use wool insulation and a vapour barrier. The general idea is that you have a gap between outer and inner leaf of walls and this does not help with insulation. Then apply a suitable plasterboard-warmboard or equivalent. It is more labour intensive but its a good job. The attic treated with sheepswool is also an area to look at aswell as is often the case if these are well insulated you will see a big improvement. EG: double insulated the attic of 3 bed semi with 2x 150mm sheepswool,put on heat at mark 5 on rads in rooms.Turned off heat after 1 hour. 2 hours later rooms dropped only 2 degrees. Before work on walls and attic they dropped by 8 degrees averager per room. Sorry to waffle on but i think the blown in is a gimmick.

Regards
Builditwell

RKQ

Excessive mortar droppings on wall ties is a problem. Each lump is a hole in the insulation.

The only cheap way to check the cavity is randomly drill holes in the wall.
There is a scope available but its expensive... not sure if you can hire them.

I'd agree with spending time and effort insulating the attic.

ellee

Can anyone advise what you should expect to pay to dry line and replaster the exposed wall in one room?

manus30

i got a lad from dungarvan insulation to give me a quote on blowing bead into my cavity walls, ie two rows of solid blocks. he said he could not do it because there is some rockwool type insulation in the cavity alreadyand the beads would just stick to the insulation. the original insualtion is not very good and comprisies of just a thin layer. is there any way of improving this or is there a different type of bead i could get pumped in?
thanks in advance

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?

Bubbles09

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?

Hi Niamh, don't even go there with the cavity insulation..
I got my house insulated its about 40 yrs old and was empty for about a year when I bought it.. My father got it insulated for me and now I have awful damp in every room.
I was told by a builder that the insulation in the cavity creates a bridge for moisture to get from the outside wall into the inside wall and that's my problem.. Only some of the windows in my house are foggy and windowsils wet etc but I'd say look at a different type of insulation and I know you can get an energy rating fella out to see if ur windows are drafy etc.. Goodluck.

goat2

chickey wrote: »

Anyone any experience of getting cavity walls in a 2nd hand house insulated? have a c.30 yr old house - which can be pretty cold - was thinking of looking in to cavity wall insulation as a means of improvement. Any got it in? does it make a good difference? what kind of price would it come at for a 3 bed semi? if anyone had any recommendations on someone doing this in Wexford better again!

Many thanks

i got it done 6 years ago, i also did the attic with the thickest insulation at that time, i now have a different home, less heating, retains the heat, the walls dont get this black mould anymore from the steam hitting cold walls, less bedclothese on bed, going for bath or shower is far more comfortable in a warm room.
now i think i should have done it 20 yrs ago
do it
you wont regret it
good luck

vinniem

Hi All, looking for a bit of advice. Trying to make house more efficient. Thinking of pumped cavity wall insulation. My house is 10 yrs old, 300mm cavity block external, 100mm outer and inner leafs, 100mm cavity with 55mm rigid insulation (polystyrene sheets) Can ye tell me firstly is it possible to get pumped insulation with insulation currently in place and secondly would it be worth my while? Thanks

mincyman

Yes you can pump in on top of insulation I done it on my house. There are loads of companies that specialise in doing it, also i came across a website that i found out about on a thread on this site called www.build4less.ie and they sell all that sort of stuff and it is way cheaper than my local harware worth a look.

vinniem

Thanks Mincyman

Upsy_Daisy

I've got somebody coming next week to insulate the cavity but I've just realised I've got no vents in any of the rooms, not sure I will get them drilled before the guys arrive to pump the walls, can i do it after?

MANSFIELD

When did 9" cavity blocks stopped being used in favour of two 4" blocks thats now being used to create a cavity wall?

Reason i ask is my house was built in 1969 and i'm wondering what type of block is used in my house. How can i check this?

Carlow52

MANSFIELD wrote: »

When did 9" cavity blocks stopped being used in favour of two 4" blocks thats now being used to create a cavity wall?

Reason i ask is my house was built in 1969 and i'm wondering what type of block is used in my house. How can i check this?

Have u any wall vents where u can take off the inner vent and look

other option is look behind sockets, after u cut the power:D

if the wall is 10" ( 9 + 1 for plaster and skim] or so then cavity block, if more then cavity wall

IMO 1969 = cavity block

brendankelly

Bubbles09 wrote: »

Hi Niamh, don't even go there with the cavity insulation..
I got my house insulated its about 40 yrs old and was empty for about a year when I bought it.. My father got it insulated for me and now I have awful damp in every room.
I was told by a builder that the insulation in the cavity creates a bridge for moisture to get from the outside wall into the inside wall and that's my problem.. Only some of the windows in my house are foggy and windowsils wet etc but I'd say look at a different type of insulation and I know you can get an energy rating fella out to see if ur windows are drafy etc.. Goodluck.

I have been saying this for years.

brendankelly

Carlow52 wrote: »

Have u any wall vents where u can take off the inner vent and look

other option is look behind sockets, after u cut the power:D

if the wall is 10" ( 9 + 1 for plaster and skim] or so then cavity block, if more then cavity wall

IMO 1969 = cavity block

The 9 inch cavity was only used for a short time in the late 70s and mostly in estates.

dathi

brendan you are right to say that 9 cavity blocks were mainly used in estates but they were used right into the late 90s in the greater dublin area, as carlow says if the wall is 250mm wide it probable is a cavity block however some of the early cavity walls were built with a 50 to 75 mm clear cavity so the only sure way is to drill a hole in to wall if its cavity block you will break through after40 to 50mm .

Build4less.ie

A good idea is the insulated the inside of the house with insulated plasterboards. This is a tried and tested method and you know you are getting all your walls insulated. Unlike blown in insulation into cavities if it gets caught on wall ties or lumps of mortar from the walls you are left with serious gaps in the insulation. When that happens you may as well not insulated.

Its hard to say what it would cost per house as every house is a different size.

If you go to our website you will get alot more information on the cost per slab. Each slab is 2.88sqm each or 2.4m x 1.2m. You can stick them to the wall or mechanically fix them with screws.

I hope this helps
Johnpaul

brendankelly

I am surprised at that because we were working in Dublin in the late 70s where the cavity blocks were used . Then dot and dab plaster board. All the talk at the time was that this system was going to be stopped. The site we were on reverted back to the 2 by 4 inch blocks and the bubble burst shortly after.

I agree with what build for less says and only if you have a cavity should you use insulated plaster board.

MicktheMan

Build4less.ie wrote: »

A good idea is the insulated the inside of the house with insulated plasterboards. This is a tried and tested method and you know you are getting all your walls insulated.

If you want mould behind the insulated plasterboards, then it is a good idea:mad:. Imo, it is misleading to say that internally insulating a house is "tried and tested" as you are increasing the risk of mould significantly.

You are also not getting all your walls insulated as there will be cold bridges at the junctions of all internal walls and floors.

brendankelly

I disagree Mick. I did my daughters house with the insulated slab system. There was rock wool in the cavities which was rotten and we were lucky that there was a strip foundation and most of it had shrunk down under the DPC. We replaced the windows so we poked the rest of it out with sewer rods. We then metalled out the walls and boarded them. It is a perfect job. There is no cold bridge in my daughters house because it is a strip foundation.

MicktheMan

brendankelly wrote: »

I disagree Mick. I did my daughters house with the insulated slab system. There was rock wool in the cavities which was rotten and we were lucky that there was a strip foundation and most of it had shrunk down under the DPC. We replaced the windows so we poked the rest of it out with sewer rods. We then metalled out the walls and boarded them. It is a perfect job. There is no cold bridge in my daughters house because it is a strip foundation.

Brendan, do you disagree that there is an increased risk of mould behind the insulated slabs or about the cold bridges?

If it is the latter, then how do you kill the cold bridge at the internal walls or do you return the insulated slabs along these internal walls (on both sides) losing even more floor space?
If it is the former that you disagree with then please explain how to mitigate against this risk when, in my experience, very few people (never mind contractors) understand moisture control and its effects in a dwelling.

brendankelly

My Post is confusing true enough. What I was trying to say was that in my opinion the only time the insulated slabs should be used is when you have a working cavity and a strip foundation. In my daughters house there was a continuous cavity all around the house with clean wall ties. There was no cold bridge at DPC level because the cavity went down 27 inches below DPC level. There was no cold bridge at the internal walls because the internal walls stopped at the cavity. There is never condensation on any of the walls in my daughters house. We did actually board the internal walls in all but one room.

Spread

Doing up a house in the country at the moment. External stone walls (22") and internal are 4" concrete block. I cut back internal walls 75mm from the externals (9 walls in all) and cut back window reveals by 50mm. Window soffits by 38mm and used appropriate thickness boards. Cut back ceiling boards by 50mm+. Mushroomed 50mm insulated boards on externals all around and made good any void at 4" blocks with s/c and 4" hession scrim. Made good to ceiling line before battening out ceiling, slabbing with 38mm boards before skimming the lot. Great result in temperature test.

Build4less.ie

If there is a concern with a cold bridge on internal walls then you have 2 options. 1. return the insulated slab down the internal wall this is better if it is only a party or seperating wall. 2. Insulate the internal stud with a glass wool insulation this will prevent any penetration of a cold bridge into the room. You would only need to insulate the internal stud about 1 meter back from the external wall. Just remove one slab on one side of the stud.

Moisture build up is prevented by using a good vapour barrier and breather membrane. Blown cavity wall insulation is inconsistent if not done properly and you never know it is not done properly until the house is knock down because you cannot see what the contractor is doing. He could be blowing in air for all the customer knows.

Build4less.ie

MANSFIELD

Build4less.ie wrote: »

because you cannot see what the contractor is doing. He could be blowing in air for all the customer knows.

So how would anyone getting this done, know that the job is being done properly?

Build4less.ie

You see that is the problem you don't. And you will probably never know. You are totally relying on the contractor doing what he is supposed to do. If he doesn't how will you ever know. At least if you use insulated plaster board you can see what is done.

Build4less.ie

brendankelly

Spread wrote: »

Doing up a house in the country at the moment. External stone walls (22") and internal are 4" concrete block. I cut back internal walls 75mm from the externals (9 walls in all) and cut back window reveals by 50mm. Window soffits by 38mm and used appropriate thickness boards. Cut back ceiling boards by 50mm+. Mushroomed 50mm insulated boards on externals all around and made good any void at 4" blocks with s/c and 4" hession scrim. Made good to ceiling line before battening out ceiling, slabbing with 38mm boards before skimming the lot. Great result in temperature test.

Was this your own house or for a client???

brendankelly

Build4less.ie wrote: »

You see that is the problem you don't. And you will probably never know. You are totally relying on the contractor doing what he is supposed to do. If he doesn't how will you ever know. At least if you use insulated plaster board you can see what is done.

Build4less.ie

You will know after about 4 years. The most problem spots are at the corners of the windows where there will be air pockets that will fill up with moisture and allow damp to cross the cavity.

MANSFIELD

brendankelly wrote: »

You will know after about 4 years. The most problem spots are at the corners of the windows where there will be air pockets that will fill up with moisture and allow damp to cross the cavity.

If thats the case,i guess its not worth getting done at all.

brendankelly

MANSFIELD wrote: »

If thats the case,i guess its not worth getting done at all.

Keep your cavity as it is . A cavity that will stop moisture getting from the outside to the inside leaf. If you already have dampness on your walls you should get this checked out first otherwise if you dry line you will have mould behind the dry lining.

MANSFIELD

I have no dampness in my walls, its just from hearing that getting the cavity filled with pumped insulation retains the heat inside the house a lot more.But no way will i get it done even if there was only a 1% chance of it causing dampness.

brendankelly

The next day you are in your hardware shop you should look at wall ties. These are strips of metal that ties the outer wall to the inner wall. You will notice that there is a twist in the middle of it. this is so the moisture will drop off at that point and drop into the cavity. In the olden days the engineer would check all the ties to make sure they were clean i.e. no mortar on them.

Spread

brendankelly wrote: »

Was this your own house or for a client???

This is my own house Brendan. From empirical evidence I know that this will work. If the house was block constructed I would have fixed resilient bar/furring first. At the windows I fixed a box frame to within 3 or 4 mm of the finish point (stopping an inch or so back from the face) inserted the insulation boards, fixed them in place with a few screws and shot foam into the void. After going off, removed screws, box frame and cut back foam before scrimming, beading and skimming. Any problems in thirty years time should be addressed to my suite in Heaven

Build4less.ie

Well if after 4 years you discover that the job is done badly where do you stand with your dodgey contractor then, nowhere. He is gone, you paid him in full for a half done job, he made double profit because he only half done your house but charged you for a completed job based on how much insulation he needs to blow into your cavity but he missed a few spots to say the least. Who suffers you. Not only have you over paid your contractor but its a double whammy cause you are also paying more on your heating bills aswell.

Build4less.ie

killyleen

manus30 wrote: »

i got a lad from dungarvan insulation to give me a quote on blowing bead into my cavity walls, ie two rows of solid blocks. he said he could not do it because there is some rockwool type insulation in the cavity alreadyand the beads would just stick to the insulation. the original insualtion is not very good and comprisies of just a thin layer. is there any way of improving this or is there a different type of bead i could get pumped in?
thanks in advance

I recently added an extension to my house. I had to cut the block so you you see where the rockwool insulation was pumped in. It had been done about 8 years previous. It was amazing how it stood up and did not fall out of cavity when we cut in to it. The rep said it was rot proof and water repellant but I would not have believed this if we had not cut wall. Most people seem to confuse fibreglass with Rockwool as in previous post.

mick121

the best way to insulate your home is external insulation.you can see each step as its on the outside of your walls.they cant miss or leave any gaps.a 4000euro grant is available.my experance with pumped insulation is stay away,they miss large areas and will there be damp problems in the long term.if a company leaves out 20% it dont sound like much,but every 5 houses they do means 1 for free.have worked in lots of homes with pumped insulation and after drilling many holes have found feck all insulation in cavity.there is also the placebo effect where if you pay big money and your told it works you will believe them.

suitseir

I am at present, looking out at my neighbour getting the pumped insulation (beads) into their red-bricked house. I think their house is over 30 years old. The van arrived at 9.00 this morning and it is my belief that if they spend the whole day there, it should be a good job. It is a two-storey approx. 1900 sq. ft.

I have been toying with the idea of getting this sort of insulation although I must say my own dormer is not as cold as other houses I have been in. It was built in 1998 and the builder I got is noted for his attention to detail, hence, during the freezing weather, I was the only one on the road who did not suffer burst pipes and had water when others had none!

I was reading these posts, old and new and just wondered if anybody who had the pumped beads would recommend them? I read an article by Ask Jeff (UK) who gives a very detailed explanation of pumped insulation giving more arguments against it than for it!!!! I suppose it is generally not proven and I would be more worried about its breakdown over the years and any health consequences in the dwelling from too much insulation.

suitseir

My brother has just got the pumped bead into his house in Cork. He says he has noticed the difference immediately. It is a detached bungalow c. 1200sq.ft. and is now convincing me to go the same route.

I am still undecided and would welcome any new testimonials......:)

tins12

suitseir wrote: »

My brother has just got the pumped bead into his house in Cork. He says he has noticed the difference immediately. It is a detached bungalow c. 1200sq.ft. and is now convincing me to go the same route.

I am still undecided and would welcome any new testimonials......:)

I would certainly go the same route as it is the cheapest form of insulation per square metre with non-invasive works and you should get your home done for around €1k depending on the size of the cavity