Timber and damp survey

[steveb]

--for the avoidance of doubt, I am not planning on having any of this work done--

Just going back through some documents from last year, we had a "timber and damp survey".

Internal Observations:
Damp
On inspection inside the building, intermittent, moderate to high moisture readings, together with visible internal defects, were noted to a number of the internal wall surfaces at both ground and first floor level.
At ground floor there are wall sections where moisture ingress has occurred and has affected internal wall plaster both rising from the ground and having penetrated through the outer walls, particularly at the front. There does not appear to be any obvious current defect causing the damp penetration around the front window area and it would appear to be because of historic defects and the type of making good which has been done previously.

In the under stairs cupboard downstairs, at the top of the stairs at first floor, in the rear first floor landing area and the rear new bedroom, there is dampness affecting internal wall coverings.
Where high corresponding ground levels exist to the left, lateral penetrating dampness is present to the walls under stairs because of hydrostatic pressure from the adjacent ground levels.
On the upper floors it appears that the replacement wall coverings have been contaminated by migratory salts and minerals from the old original masonry, which forms the outer wall abutting the adjacent building hence the incorrect type of wall covering has been applied.

A number of walls within the building have been dry lined with plasterboard or similar, in particular the retained earth walls and the old original walls thus preventing a proper inspection taking place and it is not possible to comment upon the condition of the walls behind the dry linings.

The free vertical and lateral ingress of moisture, which is able to rise in and penetrate through wall masonry by capillary action, is usually associated with the lack of or breakdown of an existing damp proof course, incorporated at the time of construction or through external defects. In many buildings prior to 1890s, damp proof courses were not included as part of the construction.
Where moisture ingress occurs either from the ground as rising damp or external defects cause penetrating damp, minerals and salts will be introduced and activated in and to the masonry, which in turn will migrate to decorations and wall coverings, causing contamination internally.

These minerals and salts are hygroscopic, which means they have the ability to draw moisture from the atmosphere, back into the wall surface.
Notwithstanding the causes of the moisture ingress being stopped and cured in the first instance, contaminated wall coverings and decoration will need to be removed to eliminate the contamination as this will continue to cause damp problem internally if not done so. Also, where high external or differing internal ground levels exist and walls are subterranean, penetrating damp will occur as a result of hydrostatic pressure. A waterproof barrier will need to be present to stop
dampness affecting wall coverings and decoration on corresponding surfaces.

and then the remediation plans are below for the ground and first floor:

Recommendations
Installing a chemical damp proof course into the walls at ground floor level, as detailed on attached plan, to stop future damp rising from the ground.
Removal of affected internal wall plaster up to a minimum height of 1.2 mtrs above corresponding ground levels to remove the salt and mineral contamination at ground level.
Removal of affected and contaminated wall coverings/plaster at ground and first floor.
Specialist re-plastering/lining system to the exposed walls to avoid further salt and mineral contamination.
Waterproof tanked protection to the subterranean walls to stop the effects of penetrating damp.
Installation of condensation control equipment

All very scary, but rectifiable for the bargain sum of about £5000+vat + redecorating everything.

So the question for you house detectives is - if you put a ladder up at the rear of the house and looked back down the external wall (from the point crudely marked with a red X and down the cruder arrow ) , what would you see...

 

[TheSpid]

The timber and damp 'specialist' running away with a boot up his backside?

 

[MikeG]

.........So the question for you house detectives is - if you put a ladder up at the rear of the house and looked back down the external wall (from the point crudely marked with a red X and down the cruder arrow ) , what would you see...

The North Sea? The Grand Union canal? A pile of earth?

 

[Clockmaster]

Install a chemical damp proof course??? These work don't they?

 

[steveb]

Mike's thinking along the right lines.

The extension at the back 10 years ago was built right up to the adjoining shop. They just put in a piece of lead, on top of the shop corrugated roof not lapped under it, and "fixed" it with bitumen or mastic.

Of course the shop roof doesn't slope towards the end of our extension so water just pools against our upstairs wall.



I don't rate the odds of an internal layer of internal "specialist replastering" fixing the problem any more than I rated the chances of an injected chemical DPC in a 450mm thick wall rubble working at the front - yet this is the standard that our "damp proof" contractors work to...

 

[Abi Cott]

I had "rising damp" in a wall in a previous property. When you took the plasterboard off the ceiling in the neighbouring kitchen extension, you could see the sky. It wasn't rising damp. It was falling damp and any numpty should have been able to tell, so nothing surprises me.

 

[steveb]

The only good advice contained in the survey was this boilerplate phrase included to allow them to probably weasel out of any guarantees:

Any existing and potential sources of moisture/water ingress must be rectified. Particular attention should be paid to the repair and/or renewal of defective roofing, rendering, pointing, gutters, down pipes, the soil/vent pipe, flashings and external joinery. A full drainage check should be undertaken regularly and any defects rectified. Unless otherwise specified within this report, all repair/maintenance work to be undertaken by Client’s own arrangements, under separate contract
and cost.

We went for that option :0)

 

[Easrow]

You would see a bit of a bodge that didn't work. When we bought our place we opted to not have any surveys done as we knew it needed work and didn't want the lenders to look too much into it. But on speaking to the estate agent when showing us around I happened to mention about how damp it was as the wallpaper was hanging off and was wet to touch. He assured me it wasn't like that when he last came...of course it wasn't Anyway, he got his mate in that was a 'damp specialist' who did a survey and found that it needed work. Suggestion was pretty much the same as above with injections and replastering etc. We got the quote and filed it in the bin. We got the house and started work and found holes all round the base of every wall and very hard plaster/tanking etc half way up. And don't forget the bitumen paint in places, flagstone floors concreted over and cracked concrete render externally. They tried selling us stuff that obviously didn't work the 1st time. We are getting there bit by bit and it's drying out nicely...without any of that extra cost and holes drilled.

 

[steveb]

oh yes, I still have the scars from trying to remove bitumen paint and waterproof plaster that had already been tried. That was an absolute dog to remove - ended up resorting to use of a hilti needle gun and pulverising it into submission until we got back to the original lime :roll: