wet insulation

[JackofAll]

So we had 80mm(a month's worth in 36hrs) of rain fall on Friday, never got to cover the cavities and the exposed insulation(knauf dritherm) is VERY wet. Will that ever dry out, some of the exterior walls were saturated.

[Marvin]

Its mineral wool

 

 

Assuming weep holes are in the bottom....

 

Check out what Knauf say.

 

https://www.knaufinsulation.co.uk/products/dritherm-cavity-slab-32

 

Allow airflow to the cavity but stop further rain: Brick on top, plastic sheet and brick above to hold plastic will do it.

 

Good luck.

 

M

[JackofAll]

On 17/09/2023 at 08:39, Marvin said:

Its mineral wool

 

 

Assuming weep holes are in the bottom....

 

Check out what Knauf say.

 

https://www.knaufinsulation.co.uk/products/dritherm-cavity-slab-32

 

Allow airflow to the cavity but stop further rain: Brick on top, plastic sheet and brick above to hold plastic will do it.

 

Good luck.

 

M

Thanks, bit of an update, covered cavities with heavy gauge polythene,called in this eve(not on site today and the wind had knocked some of the stock bricks into various spots inside the cavities. Insulation soaked and crumpled  where the bricks fell in. Have noticed that the brown colour is gone and its(insulation) now looking pale yellowy brown like the stuff it's treated with has washed out. BTW don't have weep vents.

[HughF]

Mine got wet back in June/July as the walls were going up and it washed out a bit too…. It dried out eventually 

[Mr Punter]

Use concrete blocks to hold down wide DPC over the cavity.  It will all dry out eventually.  If it got really soaked, could you drill a few holes at the bottom of the wall?

[Kelvin]

I was just saying yesterday I wonder how all the self-builders were getting on in this rain. 
 

I was paranoid about the insulation getting wet so waited until we were weathertight before fitting it. Take a wet piece and put it somewhere dry and see how long it takes to dry. I had roll that got wet on one end. I put it in the garage at home which is dry with a lot of air blowing through it. The insulation was still wet weeks later. Personally I’d be removing it but my house is a closed panel timber kit. 

[saveasteading]

I'd only add that you need evaporation upwards from the cavity, so put the polythene over it like a tent, but with air-flow between it and the wall. block/poly/block.

Perhaps drill some holes in the mortar where weep holes would be, immediately above dpc, and they can be filled again later.