Likely wall construction?

[Jack07]

Hi,
Just had an offer accepted on a house that is a 1930's ex-council house. Has a bit of damp here and there but I wanted to know what the wall construction is likely to be as I need to inject a DPC.

On outside external walls there are air bricks level with interior floor level. Does this mean they are cavity wall? Will they be brick built? Sorry to ask questions that may sound obvious but need to know before going ahead with the DPC.

Cheers Jack

 

[leew2]

Is it possible to measure the thickness of the walls? Measure it at a window or door opening. If it's 9" plus say 1/2 inch to allow for the plaster thickness then it's solid like the walls of my 1930's house (although it's not ex council).
It's highly likely it will be brick built as I believe concrete/prefab/system built/the dreaded 'non standard construction' houses came later in the 50's/60's.

 

[^woody^]

I wanted to know what the wall construction is likely to be as I need to inject a DPC.

That's a bit of a nonsense statement, as to diagnose dampness properly (and the correct remedial work) requires the wall construction to be known in the first place

The air bricks may be venting a timber floor

 

[Jack07]

I wanted to know what the wall construction is likely to be as I need to inject a DPC.

That's a bit of a nonsense statement, as to diagnose dampness properly (and the correct remedial work) requires the wall construction to be known in the first place

The air bricks may be venting a timber floor

I have had 2 damp prevention companies around to diagnose te damp, both of which said a DPC injection is needed. However, one said it is a soid wall and only needs injecting from inside, the other said it was cavity wall and needed injecting from outside also!!

Thought I would just ask on hereso when I get another damp proofer around I can question him further on it.

Also when injecting a DPC, are only the walls that are damp injected or is it best to do all the exterior walls?

Thanks again,
Jack

 

[peterperfection]

I wanted to know what the wall construction is likely to be as I need to inject a DPC.

That's a bit of a nonsense statement, as to diagnose dampness properly (and the correct remedial work) requires the wall construction to be known in the first place

The air bricks may be venting a timber floor

I have had 2 damp prevention companies around to diagnose te damp, both of which said a DPC injection is needed. However, one said it is a soid wall and only needs injecting from inside, the other said it was cavity wall and needed injecting from outside also!!

Thought I would just ask on hereso when I get another damp proofer around I can question him further on it.

Also when injecting a DPC, are only the walls that are damp injected or is it best to do all the exterior walls?

Thanks again,
Jack

Best job is to install a proper DPC course --then you will know it will work.

My tip would be to ask a reputable builder to have a look at it and avise you --rather than any tom dick or harry from ABC damp proofing company .
If you find out your house is cavity construction-- take a brick out here and there and check the cavities are not full of crap (they usually are).

I would never ever recommend having a injected DPC done - they dont work !!. There is always another cause of the damp.

 

[joe-90]

I have had 2 damp prevention companies around to diagnose te damp, both of which said a DPC injection is needed.
Jack

Well that's a surprise isn't it?

 

[Jack07]

Haha I wasnt surprised by the advice, but there is quite a lot of damp in the house. I was going to move in, get the central heating going and see the extent of the damp.

The house has been sitting for a while with a ridge tile missing, no felt or insulation etc..

So the DPC was going to be injected only if its needed after the drying out.

If it is a cavity wall, what sort of DPC would of been used if any?

Cheers,
Jack

 

[stuart45]

A council house built in the 30's should already have a DPC. The chances are that it's got a cavity wall, but it could be solid.
It's unlikely to have rising damp caused by a failed DPC.
A friend of mine used to work for BRE as a damp/timber rot specialist.
When he went out on a survey he used to take a van load of equipment, not just a damp meter which won't give you the whole story.
When called in for a second opinion on cases diagnosed as rising damp through a failed DPC he said that nearly all of them were caused by either leaking pipes, condensation or penetrating damp. Where rising damp was a likely cause it was generally high ground levels, rubble in the cavity etc.
Your average 'damp specialist' comes round with a damp meter, gets a reading and tells you to get the plaster stripped and a chemical DPC.
If you read the info on it, a chemical DPC only slows down the passage of damp.

 

[Jack07]

A council house built in the 30's should already have a DPC. The chances are that it's got a cavity wall, but it could be solid.
It's unlikely to have rising damp caused by a failed DPC.
A friend of mine used to work for BRE as a damp/timber rot specialist.
When he went out on a survey he used to take a van load of equipment, not just a damp meter which won't give you the whole story.
When called in for a second opinion on cases diagnosed as rising damp through a failed DPC he said that nearly all of them were caused by either leaking pipes, condensation or penetrating damp. Where rising damp was a likely cause it was generally high ground levels, rubble in the cavity etc.
Your average 'damp specialist' comes round with a damp meter, gets a reading and tells you to get the plaster stripped and a chemical DPC.
If you read the info on it, a chemical DPC only slows down the passage of damp.

Thanks for the sound advice stu,

Maybe I am best just getting moved in and when the heating has been running for a few weeks the majority of damp should go.

As peter suggested maybe i should remove a brick and check th cavity is clear.

On eother question, How exactly does a rusted/broken wall tile contribute to the damp? I take it also that cavity wall insulation wouldnt help the damp either? I was advised not to have it installed, anyone agree?

thanks

 

[^woody^]

If the wall is cavity, then the cavity may be blocked or breached at dpc level, in which case injection won't help at all, and there may be no rising damp.

And there are several other possible causes of dampness which will be specific to the particular wall construction

That is why the first step to proper diagnosis is to determine the wall construction