Does anyone know if cavity wall insulation can solve damp in brickwork, or will it make it worse?

EEK! I've just looked it up on google, looks like it's a no no. Maybe I should've looked it up before writing this post doh!

I have heard that some of the newer stuff makes no difference.

I would recommend a damp proof course to get rid of damp.

It is unusual for a damp course to fail. Look for other causes, broken gutters ground level etc. If your back yard wall is connected to the house and has no damp course,damp can go up and to the side overiding the damp course.A new interior floor could overide damp course if not done correctly.I would say eighty percent of damp problems are nothing to do with the damp course.

How old is the house?

It's a 1930s pebbledashed semi. I think I know what is causing the damp. The paved drive was laid too close to the damp course, so we had to chip away at it and we added a soak away layer of chippings along the side of the house. Unfortunately, some plants took hold in the chippings and I reckon their roots are hindering the soak away. Having removed them, I was wondering if the wall would dry out by itself or will I need a new damp course?

a house that old will of had the old black tar style damp course which does tend to fail around this time. I'd look in to a new damp course as there isn't really a quick fix for this. Dont what ever you do get conned in to letting some one drill holes into every brick around your house and inject crap into it...this is the cheapest and crappest method there is!

Silicon injection is the most established and proven method for a new damp-proof course on an old building. Most companies will provide a 25 year insurance backed guarantee.

The new "dutch" method of replacing some bricks with a vented air duct is not yet fully proven IMHO.

Proper replacement of the damp-proof membrane/layer is an almost impossible and very very expensive job.

Quite often the damp-proof course has been bypassed by pointing, plaster or render on the inside and/or outside, a good visual inspection can often find the culprit and is simple to remedy. Occasionally around the 1920s the outside was rendered over the damp-proof course, by now the render has lost its water-proof properties and needs to be hacked-off above the damp-proof course and a bell-cast put on (Which is just a "kicked" out section of render down to an edging).

What had you in mind instead Sanchez?

Tank the fukker ! No seriously the injection method is good but if I planned to live there for the foreseable future I'd go down the road of bricks out new damp course in. I've seen many a house with the injection method and its done nothing, but on the other hand I have seen others were it has worked well. I suppose it depends on the age and condition of the house. Any company with abit of nouse will only perform the injection method on a house they know it will work on....thus the 25year promice!

you may not have cavity walls, If they are solid and your damp course has gone it is a different ball game. vent blocks are of no use in this case anyway You are supposed to render inside,a meter or so up the walls with sand and cement. Injection is ok if done to a good standard. They used to drill the holes and just spray the bricks because there was sweet fa wrong with the damp course. guarantee is not worth a carrot but needed for mortgage or to sell. get rid of the chippings see if it dries out put a vertical damp course/run off in.

Some good advice, thanks everyone.

1930s won't have a proper cavity, it is usually a twin wall though.

Sanchez, have you ever priced replacing the damp-proof course with bricks out, plus the mess, you have to do it on inside and outside. I only know of this ever being done twice, one case was a sandstone building and was a major restoration project, the other was getting fully underpinned and had many major structural problems.

Yes, there are cowboys who don't do injection properly, yet it is a pretty easy job.

I have never priced anywork like that. I have seen it done many a time thats all.

Damp course injection if done correctly is fine. Mines a 1930`s semi, had mine done for the mortgage 10 yrs ago, not a problem. Of course depends on the contractor. Some damp can be down to BAD ventilation, make sure air bricks are not blocked and as you say, bitumen dampcourse not covered up.
I had a damp patch a while ago and couldnt work it out until realised was from the condensation from tumble dryer!! Soaking the wallpaper as far in as the hall!! Bought a condenser dryer and prob gone!! Check for hot and cold air areas!

why do all of his posts link to porn sites? stupid spam bot.

Warning: post may contain spam XD