Extremely poor quality home insulation

An interesting thread! I'm speaking as one who had cavity wall insulation installed about a dozen years ago.

I didn't like the look of the guys who did it, although they were surprisingly efficient, or should I say "fast" -- did the whole house (60s 3-bed semi) in a morning iirc).

Having read the thread so far, I expect to see the same guys (or rather their mates) again fairly soon, to "check the installation".

I have one damp patch, at the foot of the wall adjoining the house next door. Might not be to do with the CWI, but I've always had my suspicions. That wall faces directly north, and never ever gets sun.

Hey ho!

John

I was at my parents' place when theirs was done, maybe 5 years ago. They mortared the holes, and went to some effort to match the mortar colour. However, part of the house is painted render, and I was even more impressed that they mixed up render to match, and there's no colour difference. Indeed you can only see where the holes were if you look very carefully, and that's because they haven't quite perfectly matched the rough texture surrounding the hole. They also went around all the air bricks checking none were blocked. A few were, and they removed them, and inserted a giant hedgehog like brush into the cavity above them, and fitted new ones.

I was really impressed with the workmanship, and there were no subsequent problems.

I don't think PU foam has been used for 40 years. There were a few horror stories where it leaked and filled a room and set solid before anyone saw it. It also released fumes into the house for some time afterwards, which was the final nail in its coffin.

Can be for that, but its also used to reduce costs - a rendered block wall is significantly cheaper to build than a brick wall built from weather proof bricks.

By stuffing a gob of very weak mix, unmatched sand/cement into the hole.

Still weatherproof.

Jim K wrote:

It?s not that large , they did some bungalows here in the village a few weeks back an being a nosy I sod I kept an eye on how they proceeded. They worked in 3 stages with a four man team. Stage one Drilled regular 25 mm holes approx 4ft apart horizontally and 3ft vertically . On the first course of bricks above the damp course they chiselled a brick out on each corner and a couple more along the length and width. Second stage large but not excessively so vacuum inserted into the brick apertures while simultaneously a compressed air jet nozzle was inserted into the holes which the operator wiggled and loosened the fibre insulation down towards the removed bricks. One of the team was checking progress regularly using an Endoscope and I understand that the image was recorded so could be checked by others. They when happy then stuffed the 25 mm holes with a twist of insulation and made good the brick apertures. They proceeded at the rate of two properties a day. The removed insulation was emptied from the vacuum cleaners filter bag into clear plastic sacks for disposal which was one reason I took an interest, I scrounged some sacks as I intend to insulate my wooden shed by using the pond vac to blow it in between the inner and outer wooden skins, if that proves awkward then it will be used in the garden as our soil is fairly sandy and dries quickly, Mixing mineral wool into such a soil by adding to compost allegedly helps . I ?m not convinced enough to pay for any but seeing a free source it is worth experimenting. The insulation I have is clean and dry but apparently this hasn?t always been the case so it is a blanket contract.

GH

Polystyrene bead is easier, just need hoover & holes at the bottom, plus if you need to be thorough blow some air in. Hoover can be any size of course , large just makes the job quicker. The fastest option has 2 sections, clot h to let the air out then your storage bag for the beads. You don't want hi gh hoover suction if you're connecting binbags to that :) I used a handheld one to do CWI with beads, 500w IIRC.

Bead is not the best of the insulators, but it's by far the easiest to fill and to remove, and that makes it good for walls that most would not want t o CWI due to damp risk.

NT

I saw a house on the IoW once where the expanding foam had cracked the external leaf, and come out through the cracks. There was shoring holding the place up. Not quite sure why - it was obviously going to need demolition :(

Andy