Insulation Question

Insulating a garage conversion

I am coverting my garage into a bedroom and what the building to be well insulated but have limited space. The builder is insulating the roof area with 100mm insulation but suggests we should go for 25mm in the walls. Will this be enough to keep the building well insulated ?

3 Answers

Best Answer

Nowhere near enough unless you are talking about the "warm" wall which is the wall between the garage and house.All "outside walls" would require at least 80mm of celotex/kingspan type of insulation if single skin.Your roof insulation is not enough either and if its a flat roof,will need venting.There are lots of variables that cant be answered without seeing your garage but my opinion would be that you are being poorly informed.I would go for a smaller room and insulate it properly otherwise your slightly larger room will be unusable in the depths of winter.

Answered 22nd Aug 2012

Roc builders

Member since 25 Aug 2011

ROC are correct. To insulate a flat gargae roof properly you would need at least 105mm of Kingspan TR26 on top (warm roof conversion) with 100mm qit between the joist (plus a 50mm air gap).

Try emailing Kingspan or Celotex technical about your project and also speak to building control and discuss further with your builder.

If you get it wrong it will be cold and problematic for condensation.

Answered 22nd Aug 2012


Member since 26 Jul 2012

Totally agree with Roc, sounds like your getting a bad job done, also there is no way it would pass building regulations.i suggest you check a building notice has been submitted with your local council. they will come out and inspect the work before its plastered to check everything complies.

Answered 23rd Aug 2012

jd kent

Member since 14 Jun 2008

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