Recommendation needed for insulating exterior walls 1

[alexcc2000]

We are renovating a flat in the Middle East (so very hot temperature during summer 50'C), and noticed that the exterior wall was not sealed properly. This was causing hot air to and humidity to come through the walls and created mould. The builders filled the gaps and placed an insulation waterproof film.

The question is about the material to use for insulation between the exterior wall and inside plasterboard

Option a) Blue Foam (Extruded Polystyrene): Very low water absorption. Great sealant. But its flammable
Option b) Rockwool: A bit less effective insulation than Blue foam but flame retardant

ORIGINAL INSULATION WITH ROCKWOOL

After plastering and filling the gaps

After water sealant

With Blueboard

 

[LittleInch]

What's the depth of the studwork?

Compare the R value?

If you're covering it in plaster board that should be good enough fire protection long enough for you to get out.

You can get insulated plaster board, but then loose a couple of inches off the room on that wall, but might be a lot cooler.



Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[alexcc2000]

Got it! Thank you for the quick response. It's 10cm deep.

 

[LittleInch]

100mm is ok, but 150 or more would be better.

Key thing is to seal up all air gaps - that's where the heat ingress comes from.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[dik]

You have to look at the entire building envelope. I would think that if there was a low humidity, and with the high temperatures that mold/mildew would be an issue. There may be something else at play. With the temperature extremes, air barrier, insulation, sealing, and vapour barrier become quite critical.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[1503-44]

Hot temperatures are not the problem. Its the relative humidity and condensation temperature that causes trouble. Hot does increase the amount of condensation that is possible.. If you are next to the Red Sea, or the Arabian Gulf, 100% humidity is common. Air conditioning the interior, can cause condensation on the interior wall to form, if the wall temperature is below condensation temperature. It probably will be cool enough to condense. You should have an outer vapor barrier and enough insulation inside, so that cooler condensation temperatures in the interior are not transmitted through the insulation to the vapor barrier.

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[dik]

Hot temperatures are a real problem when it comes to the HVAC loading... The wasted energy is not only expended on keeping things warm.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik