Pumping Insulation query

chriscross1

i built a house 2 years ago and i put kingspan 60mm sheets into the cavity and pumped beads into the remaining 40mm space to give the house a good u-value rating, i think pumping the beads was a mistake in hindsight but i did ask my engineer if it was ok to fill the remaing cavity with the beads. anyways to the point we are getting one or two damp spots after heavy rain which i think is being caused by penetrating moisture making its way across the beads across the kingspan and finally the inner wall, the plasterer did a good job and was highly recommended so i dont doubt this. im thinking of taking the beads out if its possible and if anyone knows of a company doing this. would painting the exterior of the house with a good standard of paint eg. dulux weathershield solve this penetrating damp and save me the hassle of taking the beads out, anyone any ideas my head is wrecked, damp spots in a new house not good.help....:mad::mad::mad:

charlie40

These damp patches could also be caused by condensation or lack of ventilation in rooms

endasmail

is there a vent in the room?
forget about taking the beads out
they are mixed with a stuff that bond them together in side the wall

liveandnetural

getting out the beads is not practical post up a picture or two of the patch's so we can have a look its rare that its the insulation that causing the prob you will have to find where the water is entering the cavity first

chriscross1

charlie 40,endasmail,liveandnetural, we have vents in the windows which i leave open all the time, i didnt want vents in the blockwork as they cause draughts. im wondering how it could be ventilation or codensation as the damp spots only show up after heavy rain.. maybe there's one or two small pin holes in the plaster which would be like trying to find a needle in a haystack, maybe painting the exterior would solve that if that was the prob...when i figure out how to put a pic up on this i will..

bbam

How about a description of where the wall is damp.... is it below or near window openings or where ??
I find it hard to beleive that the damp would cross the insulation and show up after rain, I would expect a long term damp spot if this were the problem..
What about detailing on sills and the like ?

endasmail

chriscross1 wrote: »

charlie 40,endasmail,liveandnetural, we have vents in the windows which i leave open all the time, i didnt want vents in the blockwork as they cause draughts. im wondering how it could be ventilation or codensation as the damp spots only show up after heavy rain.. maybe there's one or two small pin holes in the plaster which would be like trying to find a needle in a haystack, maybe painting the exterior would solve that if that was the prob...when i figure out how to put a pic up on this i will..

no expert on ventilation
but going by what your saying ,the vents in the windows just arent doin the job
are they not there just for de misting the glass on the window itself
i dont think they were designed for venting a room

if you upload a pic to your computer
short cut on your desktop
click the" manage attachments " button in the additional options at end of page
look for your pic and upload it

mad m

Have you checked the outside render for any hair line cracks, we all know with the last snow that if rain gets into a crack then freezes it will widen the crack.

Leo Demidov

Regarding ventillation ,those window vents are "supposed" to provide ventillation equivalent to your wall vents, and by the sound of things ventillation is not the problem.

Do you have external brickwork, stonework, Granite quoins etc or as has been asked, are the leaks close to windows/doors. Waterproofing and painting your exterior may alleviate the problem but you should look for the source. Dirty wall tie maybe, not easy to track down though.

Good luck with it.

chriscross1

the damp spot is about a foot below the window sill and slightly to the right, ive checked for hairline cracks in the plaster but there wasn't any, its just plaster on the exterior of the blockwork no brick or stonework on that part of the house, could it be a wall tie, is there a crack somewhere in the windowsill that i just cant see, i used the heavy concrete window sills. the window crowd told me the vents in the windows are the required size for the room sizes. lads would there be a hole in the dpc around the window sill ?? and thats the reason it comes through fairly quickly after heavy rain

mad m

Rising damp will only go up a meter, look why don't you bite the bullet and hack out around where the damp spot is, it might be a wall tie....At least then you will know what is causing the damp spot...And then patch is up.

Is your internal finish, render and then skimmed over or was plasterboards blobbed? Sometimes you can get pattern staining with the compond that was used, where it looks like a small football hit the wall if you know what I mean....

chriscross1

the internal finish is render and then skimmed over, it might be a wall tie alright but i think its more likely there's a hole/tear in the dpc under the window sill, reason being i painted every inch of the window sill and surrounding edges of the plaster with thompsons water sealer and the damp spot hasn't come through since so surely it must be the dpc....i cant keep painting the window sill with watersealer though, as you said yourself i will reluctantly have to break the blockwork to get a look at whats going on.. thanks to one and all for the advice...

Carlow52

chriscross1 wrote: »

the internal finish is render and then skimmed over, it might be a wall tie alright but i think its more likely there's a hole/tear in the dpc under the window sill, reason being i painted every inch of the window sill and surrounding edges of the plaster with thompsons water sealer and the damp spot hasn't come through since so surely it must be the dpc....i cant keep painting the window sill with watersealer though, as you said yourself i will reluctantly have to break the blockwork to get a look at whats going on.. thanks to one and all for the advice...

Breaking the wall should be the last resort as the source of the water could be anywhere on the wall above the window.
The window reveals might not be properly sealed against plaster.

there may be a gap in plaster under sill
As noted before a picture would help.
In passing, the title of thread is not correct, the issue is damp patch, not pumped insulation

Leo Demidov

I'd love to organise a day trip to your gaff. We can all sit around ,diagnose and cure your problem, together.

It could be one of many things, all previous points being valid. Window details are notoriously **** and that was my second best guess after wall ties.

I too would be reluctant to damage any internal finishes but it may well be necessary.

Odd notion, but if you can identify likely points of ingress, you could target one point per couple of days of good weather and blast it with a power washer. Its an ignorant approach but may well work if you have the time.

From a thermographical point of view, an external survey may be of benefit but in this case may be clutching at straws.