HI I had cavity wall insulation (rock wool) removed due to damp on internal walls - all along base of the hall -which worsened when it rained . My surveyor advised the retro fittred cavity wall insultation was responsible as outside wall was sited to suffer wind driven rain. I bought the house with the problem and contacted the installers to remove under the CIGA guarantee. They agreed to remove as a good will gesture stating the insulation was not cause of damp but the wind driven rain and porous render would have been too much for the insulation and broke it down. Though inspector later advised me the wool that had been used was no longer used as it holds water, I was just happy just to get it removed. A month ago the team took it out. After a couple of dry weeks damp got much better we had rain and it all came back. I rang them they came up and looked with a camera advised me some wool was still remaining and they come to take it out. . Though the areas of damp did not relate to areas of wool left when i watched them removing it. I thought my damp problems were over and watched the lower walls all dry out again.i usea little water gadget though i know they are not considered very accurate I thought just by the pattern of readings decreasing show it is drying out. All good till we had raing again and walls looking damp again and all readings back up high. Has anyone had insulation removed and faced these issues ? does the damp go i am trying to understand if I should be contacting the insulation company again or exploring other options and considering my surveyor/home buyers report and the supporing damp survey i also obtained had the wrong cause of the damp ? Help anyone ?
Damp -Route cause ??
- Thread starter clearskys
- Start date
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Ask the mods to transfer this post to the building forum.
Anyway, was the cav insulation applied to all the elevations at full cavity height?
Did you take the trouble, its your house, to peer up and around the cavity when they removed patches of brickwork?
Are you saying that some wool was purposely left in the cavity?
If the prevailing conditions - wind, render whatever - were too much then the insulation should not have been installed in the first place.
Did you sign anything agreeing that the remedial work would be a gesture of goodwill?
Anyway, was the cav insulation applied to all the elevations at full cavity height?
Did you take the trouble, its your house, to peer up and around the cavity when they removed patches of brickwork?
Are you saying that some wool was purposely left in the cavity?
If the prevailing conditions - wind, render whatever - were too much then the insulation should not have been installed in the first place.
Did you sign anything agreeing that the remedial work would be a gesture of goodwill?
Thank you I will ask them . The insulation was throughout the walls up to roof. They left some wool in by mistake . I thought that if the insulation was removed rain penetrating the outer wall would not pass through to the interior walls ? Is my understanding wrong ? They did advise me it would take couple of months to dry out . It has been 6 weeks now . Reason why I am so concerned is I have been doing damp readings all was decreasing till we had rain now it is back high again do logically I think rain is still penetrating ? The insulation was in when I bought the house because surveys said damp was due to it and u spike to surveyor he said not a major damp issue get the insulation out . So I bought it and when through process if getting it removed under the ciga guarantee . Now I don't know if I need to be looking for other causes ? I know rendering needs redoing but planned to do it next year when all work inside was finished not going make any more holes new boiler etc . But really concerned now in case water doing damage I cannot see also . Be greatful of any advice
Moderator please can you move my posts/ thread to the build forum thank you
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How do you know that "They left some wool in by mistake"?
You have a cavity wall that has been rendered - typically, a cavity wall would not be rendered unless there were issues such as penetrating damp. Only posted pics of your rendered walls would indicate their condition.
Depending on the condition of the render and brickwork, wind driven rain can indeed blow through render and outer brickwork to the inner skin.
Piercing holes for boiler flues etc has no bearing on this issue.
Many cavities are blocked and bridged by debris and dirty ties from new build. Failed or rusted cav ties will aso transfer moisture to the inner skin of brickwork.
The cavity insulation company pre-installation inspection/survey should have used a device to inspect the condition of the cavities.
Call a local builder who owns and uses a Borescope to inspect your cavities.
You have a cavity wall that has been rendered - typically, a cavity wall would not be rendered unless there were issues such as penetrating damp. Only posted pics of your rendered walls would indicate their condition.
Depending on the condition of the render and brickwork, wind driven rain can indeed blow through render and outer brickwork to the inner skin.
Piercing holes for boiler flues etc has no bearing on this issue.
Many cavities are blocked and bridged by debris and dirty ties from new build. Failed or rusted cav ties will aso transfer moisture to the inner skin of brickwork.
The cavity insulation company pre-installation inspection/survey should have used a device to inspect the condition of the cavities.
Call a local builder who owns and uses a Borescope to inspect your cavities.
Hi this is my render
Thank you for the pics. Unfortunately they are only pics of two partial elevations.
You have a dashed render that was part of the original house build. The dashed render appears to be in excellent condition -why was retro cav insulation thought necessary? Do your neighbours have similar retro cav insulation?
I can see the installation holes but where are the "openings" that were used to remove the cav insulation?
The tile creasing line that projects from the face of the elevation will be introducing moisture into the cavity - its a very poor design feature.
The tile creasing has been smashed to allow the RWP to drop through - very rough work.
Who introduced the air bricks at that level, and what is their purpose?
You have a dashed render that was part of the original house build. The dashed render appears to be in excellent condition -why was retro cav insulation thought necessary? Do your neighbours have similar retro cav insulation?
I can see the installation holes but where are the "openings" that were used to remove the cav insulation?
The tile creasing line that projects from the face of the elevation will be introducing moisture into the cavity - its a very poor design feature.
The tile creasing has been smashed to allow the RWP to drop through - very rough work.
Who introduced the air bricks at that level, and what is their purpose?
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