External insulated plaster on walls 18" thick?

dave 27

Hi all, recently bought a house and we are going through different options to better insulate the house, there are two walls of the house which are 18" thick and so we cant pump them as there isnt any cavity, our options are.

1 - Install insulated plasterboard internally but it is extremely intrusive or

2 - Install external insulated render to the 18" walls, only thing is as the walls are so thick and the insulation is outside, would this work as well as intended as the heat will still escape the room and through the wall?

BryanF

2. Wall thickness no issue. It’s the more complete thermal solution. Google the benefits of thermal mass.

Builderfromhell

Externally insulate but you might need someone to advise or produce details for the contractor as it's not always done right. I would suggest moving windows and doors out to where EI meets the walls to avoid thermal bridging. Also bring EI under ground outside about 300mm, again to avoid thermal bridging

893bet

If the walls are 18 inch thick uninsulated what’s under the floor?

dave 27

893bet wrote: »

If the walls are 18 inch thick uninsulated what’s under the floor?

It's a dormer, originally a small stone built house with concrete floors that had been extended in the 90's, so the back of the house have cavity walls but the front part has stone