Timber frame insulation

Builderfromhell

I am building a timber frame house which comes with standard 150mm fibreglass insulation. There is an option to upgrade to other types of higher grade insulation. I am thinking of ordering TF house without insulation and insulating muself with one of the following;
1. Sellulose insulation sprayed between studs. Advantages; breathable, all gaps sealed, environmentally friendly (recycled paper).
2. 150mm Kingspan or Quinntherm (polyuretane insulation). Dis-advantages; difficult to fit tightly between studs.
3. 150mm fibreglass with 35mm (I think) Kingspan plasterboard sheets screwed to studs.

Would love to hear opinions and views, especially on cost comparison. I can look at U-values later.
Thanks.

Do-more

I have cellulose insulation in my frame BFH and find it excellent. The house certainly holds the heat well between heating cycles.

I often wonder if the cellulose has sagged or slumped leaving a gap at the top of the frame, (the house is now 5 years old) I'm not suggesting it has or that there is any evidence that it might, I just wonder...

I've thought about getting a thermal image of the house done to check but never bothered to go to that expense.

I'm sure the same can happen with glassfibre aswell, how many installers do you see stapling the glass mat to the top of the frame?

As you point out yourself the problem with Kingspan is cutting it to fit without any gaps.

I think if I was building again in the morning I would use the very high density Rockwool or Paroc type insulation, the problem of course is the lack of availability in this country.

Might be an idea to chat to one of the companies that do thermal imaging to see if they can give you any "insights" as to what they have found in the past...

ardara1

Builderfromhell wrote: »

I am building a timber frame house which comes with standard 150mm fibreglass insulation. There is an option to upgrade to other types of higher grade insulation. I am thinking of ordering TF house without insulation and insulating muself with one of the following;
1. Sellulose insulation sprayed between studs. Advantages; breathable, all gaps sealed, environmentally friendly (recycled paper).
2. 150mm Kingspan or Quinntherm (polyuretane insulation). Dis-advantages; difficult to fit tightly between studs.
3. 150mm fibreglass with 35mm (I think) Kingspan plasterboard sheets screwed to studs.

Would love to hear opinions and views, especially on cost comparison. I can look at U-values later.
Thanks.

Don't use your PIR between - you're right - it'll be expensive to fit with not great benefit - but if you use only standards fibre at 140mm (Your stud depth) you'll only achieve 0.32 (YOu won't even meet the regs) use a good HD fibre (Frame therm for rigidity) and line with 30mm Xtratherm Kingpsan type material - you'll get 0.19 - a dramatic improvement - simply because you're covering the studs that are a significant thermal bridge (min 15% of the total wall are - probably much higher)

YOu MUST have vapour control layer to the inner face of the construction - this also acts as your air barrier (See accreditted details on Planning Portal) - using a composite plasterboard/pir insulation slab does not constitute a continuous barrier (gaps between the foil) either put polythene sheeting on - then liner or put insulation on first - tape joints with aluminium tape the plasterboard. to do it properly, put battens OVER the insulation before you put plasterboard on - you've then got an insulated service duct into which you run your services maintaining the integrity of the VCL (an improving the U-value)

Builderfromhell

That's good advice guys.
Two questions.
Does Cellulose insulation between 150mm beep timber frame exceed current building regs?
I always considered PIR insulation board to also act as vapour barrier as long as joints are taped with aluminium tape.
However, I have read elsewhere that in the USA Timber frame companies are being sued for building houses to details commonly used in this country. Vapour travels through holes in vapour barrier (service openings) and condenses on frame leading to wood rot.
I have much experience in building and find it almost impossible to stop subcontractors from piercing vapour barrier. For example; Electrical sockets, switches, cables, air vents, rads fixed to frame, pipes through walls.
For this reaason I am leaning towards a breathable wall that allows vapour to pass through. This is one reason I am considering cellulose.
I feel the issue of correctly insulating timber frame houses (and indeed all wall types) is becoming more critical as houses are better sealed and better insulated. Condensation is/could become a serious problem.

CJhaughey

You need a HRV system that runs a slight underpressure in the house, this stops water vapor from being forced into the fabric of the house.
If you are building in this manner you will need to have HRV installed anyway.

Mellor

Builderfromhell wrote: »

I have much experience in building and find it almost impossible to stop subcontractors from piercing vapour barrier. For example; Electrical sockets, switches, cables, air vents, rads fixed to frame, pipes through walls.

I think you are refering to the wrong membrane here.
You should never use a vapour barrier in a wall. You need a vapour control layer, this completely different. For a start, piercing it with services is not as big an issue. It doesn't prevent vapour crossing, but rather controls is passage by restricting it to an acceptable level.

ardara1

Builderfromhell wrote: »

That's good advice guys.
Two questions.
Does Cellulose insulation between 150mm beep timber frame exceed current building regs?
I always considered PIR insulation board to also act as vapour barrier as long as joints are taped with aluminium tape.
However, I have read elsewhere that in the USA Timber frame companies are being sued for building houses to details commonly used in this country. Vapour travels through holes in vapour barrier (service openings) and condenses on frame leading to wood rot.
I have much experience in building and find it almost impossible to stop subcontractors from piercing vapour barrier. For example; Electrical sockets, switches, cables, air vents, rads fixed to frame, pipes through walls.
For this reaason I am leaning towards a breathable wall that allows vapour to pass through. This is one reason I am considering cellulose.
I feel the issue of correctly insulating timber frame houses (and indeed all wall types) is becoming more critical as houses are better sealed and better insulated. Condensation is/could become a serious problem.

Hi Builder - the British agrement for Warmcell gives it a thermal performance of 0.036 Lambda - when you put that into a 140mm stud - Based on the BRE Paper SD2 -
0.035 get a U-value of 0.28 and 0.04 achieves 0.30 (But they are based on UK 600mm centres - you're are perhaps 400mm (More bridging)

In the US - depending whaqt climate zone you're in the VCL can be placed either internally - or even externally - have a google for Building Sciences Timber FRame.

In UK and Ireland TF must have a VCL to the inner surface, tests carried out on moisture movement in timber frame have looked at the less than perfect VCL scenarios and any moisture dissapates over the summer months in any case.
Remember when you put a layer of plastic on th internal surface the pressure within the home is separated from the pressure on the other side of the VCL.

Builderfromhell

ardara1 wrote: »

Hi Builder - the British agrement for Warmcell gives it a thermal performance of 0.036 Lambda - when you put that into a 140mm stud - Based on the BRE Paper SD2 -
0.035 get a U-value of 0.28 and 0.04 achieves 0.30 (But they are based on UK 600mm centres - you're are perhaps 400mm (More bridging)

In the US - depending whaqt climate zone you're in the VCL can be placed either internally - or even externally - have a google for Building Sciences Timber FRame.

In UK and Ireland TF must have a VCL to the inner surface, tests carried out on moisture movement in timber frame have looked at the less than perfect VCL scenarios and any moisture dissapates over the summer months in any case.
Remember when you put a layer of plastic on th internal surface the pressure within the home is separated from the pressure on the other side of the VCL.

That's interesting info.
I am really looking for an insulation solution that I am happy to apply to all new build.
Currently I'm thinking ;
150mm timber studs with rockwool or warmcell insulation.
Vapour barrier on internal face of stud, aluminium foil or similar would be good as would reflect radiant heat back into room.
Plasterboard on 50x25mm battens on studs, this gives me a gap to run small pipes and cables.
VP should not be penetrated.

However, Since reading the above posts I am also thinking ;
Heat exchange ventilation system may eliminate most water vapour form all rooms.
Omit VP and use Breathable insulation with usual Tyvek breathable membrane outside OSB.

I much prefer to let building breath

ardara1

Builderfromhell wrote: »

That's interesting info.
I am really looking for an insulation solution that I am happy to apply to all new build.
Currently I'm thinking ;
150mm timber studs with rockwool or warmcell insulation

YOu can't get 150mm studs - don't do your calc based on this - 140mm finished.

Vapour barrier on internal face of stud, aluminium foil or similar would be good as would reflect radiant heat back into room.

Foil is benefite ONLY when reflected back into a VOID - if it's cover (in a floor - or with plasterboard - it's of NO BENEFIT)

Plasterboard on 50x25mm battens on studs, this gives me a gap to run small pipes and cables.

INsulated service void - great idea.

VP should not be penetrated.

However, Since reading the above posts I am also thinking ;
Heat exchange ventilation system may eliminate most water vapour form all rooms.
[Omit VP and use Breathable insulation with usual Tyvek breathable membrane outside OSB.

NO - you must have a Vapour COntrol Layer to the Inner face - AND you MUST have a breather membrane out side the OSB

I much prefer to let building breath

It's a theory held by a VERY few people - why not go with the majority of government bodies and timber frame associations and timber frame manufacturers - just in case.

YOu seem to have made up your mind about the MVHR - how are you going to get the air tightness in timber frame without a VCL? - you'll simply be blowing air through the walls. Air permeability needs to be better than 4 before MVHR becomes of any benefit - otherwise you're blowing air into a sieve.

Mellor

Builderfromhell wrote: »

That's interesting info.
I am really looking for an insulation solution that I am happy to apply to all new build.
Currently I'm thinking ;
150mm timber studs with rockwool or warmcell insulation.
Vapour barrier on internal face of stud, aluminium foil or similar would be good as would reflect radiant heat back into room.
Plasterboard on 50x25mm battens on studs, this gives me a gap to run small pipes and cables.
VP should not be penetrated.

However, Since reading the above posts I am also thinking ;
Heat exchange ventilation system may eliminate most water vapour form all rooms.
Omit VP and use Breathable insulation with usual Tyvek breathable membrane outside OSB.

I much prefer to let building breath

Two things BFH, have a look at my posr #6 above. You keep refering to a vapour barrier, this is wrong. A vapour barrier doesn't go in a wall. You need a vapour control layer, while similar it has a critical difference in that it allows some vapour through, at a controled rate.
You need a VCL to the inside, the breather membrane is to the outside and is optional. This still allows a building to breath, it just restricts the flow. (think of a gas mask )

THe other thing is to back up what Ardara said about Alu foil. It will only reflect radiant heat back when it is in a void, ie an exposed surface. When sandwiched between elements it will have little effect.
Also, as said it reflects radient heat. This is heat emmitted from a warm body (any body, not just people), in a building this make up for a tiny amount of heat loss, most of the heat is lost through conduction and convection.

Builderfromhell

Thanks for the advice guys.
Their would be a gap between the foil and the plasterboard of 25mm. This gap is created by fixing 50 x 25mm battens to the studs after the foil had been stapled to the studs.
I did not realise that so little heat is lost by radiation. Might be wise to put foil where there are rads only.
In view of the above posts, I'm thinking the TF std. details are probably as good as it gets.
140mm deep studs
cellulose insulation between studs
and
where client decides to pay for extra insulation I am considering Kingspan Kooltherm K17, 32mm sheet or similar dry-lining sheets with plasterboard. These are the composite boards with rigid insulation and plasterboard.

Again, I prefer not to use materials which while being excellent insulators may trap moisture or/and outgas toxic chemicals to building for years.

sydthebeat

Builderfromhell wrote: »

Thanks for the advice guys.
Their would be a gap between the foil and the plasterboard of 25mm. This gap is created by fixing 50 x 25mm battens to the studs after the foil had been stapled to the studs.
I did not realise that so little heat is lost by radiation. Might be wise to put foil where there are rads only.
In view of the above posts, I'm thinking the TF std. details are probably as good as it gets.
140mm deep studs
cellulose insulation between studs
and
where client decides to pay for extra insulation I am considering Kingspan Kooltherm K17, 32mm sheet or similar dry-lining sheets with plasterboard. These are the composite boards with rigid insulation and plasterboard.

Again, I prefer not to use materials which while being excellent insulators may trap moisture or/and outgas toxic chemicals to building for years.

perhaps consider swapping the kingspan composite board with woodfibre insulation between battens.... because all your other construction is breathable but the kingspan isnt.

Builderfromhell

Thanks Sydbeat. I'll Google woodfibre insulation board for suppliers. Do you, or anyone else, know where it can be sourced. I'm in Limerick.

sas

Builderfromhell wrote: »

Thanks Sydbeat. I'll Google woodfibre insulation board for suppliers. Do you, or anyone else, know where it can be sourced. I'm in Limerick.

http://www.ecologicalbuildingsystems.com/products/holzFlex/

Be sitting down when you price it!

TERRIC

INSULATION - PLEASE HELP!!

can anyone give me some idea of how much insulation i will need to get for a new-build 2400 sq foot storey and a half house.

What type?
Where?
How Much?

Have no idea where to start. All i do know is that money is running out fast....!!

sydthebeat

TERRIC wrote: »

INSULATION - PLEASE HELP!!

can anyone give me some idea of how much insulation i will need to get for a new-build 2400 sq foot storey and a half house.

What type?
Where?
How Much?

Have no idea where to start. All i do know is that money is running out fast....!!

you need to get a DEAP (Dwelling Energy Assessment Procedure) calculation carried out.

This will tell you exactly what material and thickeness needed to comply with minimum regulations. It can also tell you what upgrades you can make to bet to a preferred BER rating.....