Questions about the weeks and months after extraction. The pages on drying out, re-insulating or leaving clear, making good and airbricks go deeper.
How long until the wall is dry?
The cavity air dries within weeks once it is open. The masonry takes far longer: the damp trade’s rule is a month per 25mm of wall thickness, so allow a good many months and do not plan on final decoration for a season or more on a badly wet wall. Readings against the survey grid show the trend.
When can I decorate?
A plain, non-vinyl emulsion after a few weeks if the stain bothers you, and proper decoration when the wall reads dry through its thickness. Wallpaper on a damp wall lifts; vinyl paint traps moisture.
Will the stains go away?
Stains and salts often get worse as the wall dries, because the water brings them to the surface on its way out. That is normal. Salt-contaminated plaster may need replacing once the wall is dry; the survey tells you whether we think it will.
Should I refill the cavity?
Not until the wall is dry and the outside defects are fixed, and not at all on a wall where the guidance says fill was never suitable. Refilling with thermal bead is part of our own job if you want it, and it happens once the cavity is clear and the wall is ready to take it. Leaving the cavity clear is also an option, and where the survey says a wall should not be refilled we say so.
Will my heating bills go up with an empty cavity?
Compared with dry, working insulation, somewhat. Compared with wet insulation, which conducts heat out of the house, most people see no increase and often a fall once the wall dries.
What about the wall ties?
We look at them with the borescope during the survey and the extraction. Ties that are rusting badly are reported, because they are a structural matter. Replacement is a specialist job and not ours.
Will the brickwork look different?
The reinstated bricks are the originals. The new mortar shows for a season or two until it weathers, more on an old lime-pointed wall. We match as closely as the wall allows and say on the day how visible it will be.
Do you fix the plaster inside?
No. Plaster comes off and goes back on once the wall is dry, and that is a plasterer’s job. The quote says whether it is likely to be needed.
What if damp comes back?
Tell us. If the cavity is clear and the outside is in order, a wet patch after a full dry season is unusual, and we would come back and look with the borescope. Our own workmanship is covered by our guarantee.
Do I need to do anything to the airbricks?
We clear them and sleeve them where the floor is suspended timber as part of the job. Keep the outside of them clear of soil, leaves and raised paving afterwards.
How quickly will you reply if I have a question after the work?
We reply within one working day to arrange a free survey and quote.
