Concrete Roof advice

[foxydan]

Dear all,

I need some advice on best approach to insulate a concrete roof. We have a house in France that includes a concrete terrace (about 4-6inch thick). There is no way to insulate above it and effectively raise the roof as this area is used, has doors into the property off of it etc.

top of terrace deck

• foxydan
• 27 Dec 2020

Underneath the terrace is basically a garage that I want to convert into a gym. The outside wall is single skin breeze block and a solid concrete roof (top of terrace). My questions are around how to insulate it - particularly the concrete ceiling. I've attached some pics to help explain what I mean.

garage door

• foxydan
• 27 Dec 2020

Can anyone shed some advice on the best way to go about insulating the ceiling? There is very little headroom and the floor will be dug out at some point for a new slab inside. There is already water from the terrace above that seems to come through so was thinking about getting this repaired and properly sealed. i just don't know the best thing to do below it, in terms of insulating, ventilation and options available. There isn't a lot of head height to work with.

inside underneath 3

• foxydan
• 27 Dec 2020

inside underneath 2

• foxydan
• 27 Dec 2020

inside underneath

• foxydan
• 27 Dec 2020

Any help would be appreciated.

 

[KenGMac]

Suggest you have a look @ the attached, may give some ideas on materials and installation?

https://www.kingspan.com/gb/en-gb/p...ds/kooltherm/kooltherm-k110-plus-soffit-board

 

[foxydan]

Does this attach straight to the concrete then?

 

[catlad]

Glue the insulation to the ceiling with expanding foam.

 

[Notch7]

I would love to have a place like this in France

 

[foxydan]

Ok thanks so far. So with this stuff, I shouldn't have any problem with condensation/water vapour? Just trying to understand the joints bit...sorry for the questions!

 

[foxydan]

I would love to have a place like this in France

It would be nice to be able to get there! Who knows when I will next be out there!

 

[KenGMac]

Think you will find a load of Info in the following.


48491_ProductBrochure_KoolthermK110PLUS_UK

 

[foxydan]

Many thanks for all your help...Am I then able to just plasterboard over? How would you do this considering there are no battens?

 

[Mr Chibs]

I think it will be a bit of a struggle to glue these to the ceiling. You may need quite a few props to keep it tight to the ceiling once you’ve squizzed some foam on.

Lots of insulation boards are not totally flat, most have a bit of curve to them and the thicker the board, the harder to straighten.

it will also require some mechanical fixings, proper insulation/render fixings.
To make sure it all stays put.
Not an easy drill into concrete.

You can then bond the plasterboard to the insulation boards.
Either with foam, or if using non foil board plasterboard adhesive.

Good luck.

 

[catlad]

I can recommend Piher multi props if you want to prop things or clamp things, unlike other props these are like mini acrow props 450kg and can by tightened.
I have several different sizes now and its one of the best things I have bought.
ps. never use normal plaster board on roofs.