Unprotected concrete block walls and damp?

Gorie

I am considering buying a new build house (2 years old).

Part of the external wall at the rear, the bottom part concealed by a party wall, is constructed of concrete blocks !As far as I can see the wall is not rendered !so I can see the concrete blocks. !The upper part is made of brick (expensive reclaimed ones).

The un-rendered concrete block part is about 1-2 inches away from the party wall at the boundary of my land. !As the party wall is parallel and close to the entire concrete block part it seems somewhat protected. !The gap is a little protected from above by my roof gutter. !But there is still a gap and water could get in.

Is this common practice or acceptable? !!

Is there anything that could be done to protect this part of the wall? !It would be hard to paint with chemicals or render as you cannot get into the space between it and the party wall. !I could put lead flashing across the top to close the area off but I'm not sure what the neighbours would think?

My surveyor seemed to think with a gutter between the two Walls it would be fine. !

I have been inside the house and it seems dry, but it is dry-lined so I guess It would be difficult to tell.

I really like this property and it is perfect otherwise but I'd hate it to become damp or be an issue if ever I sell it. !

Any advice would be greatly appreciated! Thanks

G_M

Gorie wrote: »

My surveyor seemed to think with a gutter between the two Walls it would be fine. !

I have been inside the house and it seems dry, but it is dry-lined so I guess It would be difficult to tell.

You've had a survey done !And the surveyor says it's fine but you are still worried !

Why does dry-lining make it difficult to tell - either it is dry inside, or damp !Did your surveyor test for damp? Have you looked for peeling paint/wallpaper? Smelt damp? If it seems dry it is probobly..... dry ! What's the problem?

And what makes you think concrete is not s uitable material for an external wall ?!

casper_g

There are different types of concrete blocks. Lightweight "breeze blocks" with cinders added would be unsuitable for an external wall, but dense concrete blocks will be fine. It's fairly well known that modern buildings often have exteriors made from concrete, and have done for a good few decades now.

As long as your surveyor is happy that the right kind of blocks have been used, the only disadvantage of concrete blocks is the way they look. As you'll only see them from the inch-wide gap adjacent to the party wall, this doesn't seem to be a problem!

Gorie

I am always a little dubious of surveyors as they use the words probably and might so you never really have any comeback.

My surveyor said "it seems dry and tests dry, but as there is most likely a form of sealing membrane at the back of the drywall it can be hard to tell if some damp is present".

I was under the impression that concrete blocks were more pourous than brick and might draw water in if it got down there.

You are right thou, perhaps I am a little to anxious. I'm just scared as it's my first house.

He advised a drainpipe and more flashing to protect the area also

Gorie

The walls are plaster and do look dry also

Many thanks for your responses and advice!

G_M

Gorie wrote: »

My surveyor said "it seems dry and tests dry, but as there is most likely a form of sealing membrane at the back of the drywall it can be hard to tell if some damp is present".

I just don't get this. If there is a sealing membrane - presumably put there to keep any moisture on the outside from coming to the inside - then if the inside "seems dry and tests dry" then the sealing membrane is clearly doing its job.

The point is, THERE IS NO DAMP ON THE INSIDE. Whether this is due to the external material (concrete) keeping moisture out, and/or effective pointing, and/or a the sealing membrane does not really matter does it? THE INTERNAL WALL IS DRY.

Reminds me of last week's "Rogue Traders". Damp proof 'specialist' showed gullible old lady that her external brick wall was damp following rain. Of course it was - external walls get wet! The question he should be asking is 'does the internal wall get wet?'