Injected DPC

[xanthe]

From what we can tell, the current owners of the property we're buying did lots of work back in about 2003 including an injected DPC - including replacing the internal lime plaster with modern; treated the timbers for woodworm and death-watch beetle; repointed the whole property in cement and so on.

The DPC and the timber treatment both come with guarantees and for a fee we could have these transferred to us.

The injected DPC was to the front and one gable wall. The holes can be seen at ground level along the brickwork. The floor-level in the house is lower than this, and there is also a large cellar directly underneath.

There is some damp in the cellar, but removing vegetation along the wall where the vents are, removing all the cement pointing from the ashlar (which is causing the walls to be wet and the surface of the ashlar to start spalling) and putting in a decent ventilation system should deal with that. Otherwise, the house is pretty dry everywhere and removing the cement and repointing in lime should help that.

The surveyor's view was that there had been woodworm, death-watch beetle and a load of other beasties, but not for a very, very long time.

I have a couple of questions.

a) is there any point in paying for the guarantees to be transferred over? The beetle treatment appears to have consisted of spraying the beams with chemicals - from what I have read, it seems that getting rid of DWB is considerably harder than that.

b) is an injected dpc any use if it is put in above floor-level in a wall that has a cellar below it?

c) is an injected dpc even a good thing in the first place? Can I repair the damage? Fortunately the holes in the bricks aren't too obvious.

Thank you for any advice.

 

[plasticpigeon]

In my opinion all those methods are scams, and the guarantees useless. I've not heard otherwise from anyone else. If you fix the house properly 9which it sounds like you are) then that is the best insurance against future problems!

 

[mattice]

We paid £100 to transfer our guarantees 'just in case'. If you read the wording it would be practically impossible to make a claim. Two terms stand out for the damp guarantee .

1) any works in the vicinity of the remedial work invalidate the guarantee
2) damp has to be reported within 14 days of it occurring. Almost like it's been on holiday and suddenly decided to come back :lol:

Ours was also injected above floor level on internal walls, and it's failed, where as other corrective actions as you suggest are making good progress.

If you intend to sell within the period of the guarantee and intend to comply by its terms, itmay be worth stumping up the cash as it pacifies some buyers. I'd done a lot of research prior to purchase, and despite understanding the pitfalls of such treatments, I used it as an excuse to buy anyway ;-)


Good luck.

 

[xanthe]

I shall save the pennies then and put them towards some nice caulking

Can an injected dpc actually do harm to a building? Is there something I can do to 'repair' the damage? I'm presuming that removing the nasty modern plaster is not a problem.

I'm also wondering what to do about modern gloss paint on C17th bricks. There's no insulation on the inside of the brick infill panels and in the attic room the owners have painted the bricks bright white. I don't want to damage the bricks by removing it, but I'm also unhappy about a layer of plastic over them.

 

[TheForge]

Absolutely no value in paying for a guarantee on something that was never going to work in the first place. If it 'fails' what will they do? Drill more holes?! That's assuming the company even still exist.

Injected DPCs reduce the integrity of the masonry - drilling a series of holes will weaken any substrate.

 

[xanthe]

Company still exists - reading their website put me off even more. The more I read, the more horrified I am about the whole damp-proofing industry. How do they get away with what seems to be a complete scam?

My parents seem to be being advised to put various damp courses in their listed properties (one a C13th Devon cob that has appalling damp and the whole outside is concrete render that the surveyor has advised them not to remove). I've told them not to do anything till I manage to get a decent conservation person in to advise them properly.

Other than the annoying little holes in the bricks, are there any downsides to the DCP or can I just carry on as if it doesn't exist?

 

[TheForge]

A DPC in soft wet cob will do nothing and will just undermine the wall while letting even more water in behind the cob.

Where a outs in Devon are they? I can put you in touch with some 'experts' in the area.

 

[xanthe]

They're near Ottery.

Would love some names - I'm very suspicious about some of the things that both the architect and the builder have been saying. Then tend to 'fall in love' with their contractors a bit and then can't quite deal with not going with what they are told to do and feel disloyal by seeking advice elsewhere or saying they want to do things differently.

I've suggested to them that before committing to anything that they get some second opinions. They've said that they are prepared to do that (started by saying they'd ask the architect what he thought of them first :roll: ).

There are 2 properties, one is a thatched cob cottage - cement rendered, v neglected, lots of damp and the thatch needs replacing completely. The other is late Georgian, also damp and has been just about maintained. They are doing up both, starting with the Georgian.

Architect has strongly warned them away from using sheepswool as an insulating medium and is recommending some modern stuff (APs can't recall name) and the builder has recommended that they put in a damp course using terracotta pipe sections stuck in everywhere :shock: . Neither are specialists in old buildings from what I can gather.

I've recommended that they clean all the cement and similar off the place and look at natural methods before putting in damp courses etc.

 

[Flyfisher]

Charging to transfer the guarantee sound like a scam in itself. Why should it matter who actually owns the property? It's not exactly mobile is it, so it's not going to be easy to lose track of it!

 

[plasticpigeon]

Whatever they decide, please make sure that no holes are drilled in bricks, and no pipe sections are stuck into the walls, compromising the integrity of the brickwork. That a very expensive and permanent way to to ruin the house.

 

[xanthe]

My thoughts exactly FlyFisher.

I imagine they had a survey done back when they bought the place with all the usual caveats and suggestions of having timbers and damp looked at by specialist companies... and bingo... kerching!

That's what I'm worried about plasticpigeon - they're going to pay a fortune for something that a) doesn't need doing b) is going to do nothing about damp and c) is going to actually damage the house. They seemed really surprised when I said the pipe malarkey was ineffective and not something to touch with a barge-pole. I've sent them a link to Heritage House as he spells things out pretty well about damp proofing and old properties.

 

[TheRoost]

c) is an injected dpc even a good thing in the first place? Can I repair the damage? Fortunately the holes in the bricks aren't too obvious.

On my house they filled the holes with coloured sand/cement mix that was so soft it just fell out as loose sand, and was home for various insects! I scraped it all out and then packed with lime mortar to hopefully restore some of the strength.

 

[SilverSaloon]

I'm current hacking off all the cement render off the interals of my stone built cottage and filling in the nasty DPC injection holes with lime mortar.

 

[drpepe]

I'm current hacking off all the cement render off the interals of my stone built cottage and filling in the nasty DPC injection holes with lime mortar.

Any ideas what would be the best off the shelf (i.e. easy to mix) product for exterior DPC holes? What's the best way to colour it to match various materials?

e.g. stone, mortar and ?bath stone

 

[livias]

I would poke around in the shed for something to use as a setting agent and/or filler. It is not doing much other than hold the colour in position so ... exterior polyfilla or some other gunk which is a reasonable colour

To get the right colour best is to mix in dust from the stone or brick that you are trying to match but I would not be too fussy and a suitable acrylic paint possibly artists paint with a fine paintbrush would be ok. Once it is done you will never look at it again

Anna

 

[xanthe]

Thanks - will do some filling with lime when we get the house repointed!

 

[SilverSaloon]

If just to fill all the DPC holes, i would recommend getting some ready mixed lime mortar and making up some of that and pushing it into each hole until its filled with your fingers.

Many places do a colour match service or have a colour chart to choose from.

 

[vicky whitworth]

Hello,
If your parents are near Ottery try www.davidjoycecobandlime.co.uk He's a really good guy - sensible, quiet, knows his stuff. Has done plenty of work on our rubble stone cottage near Axminster.

 

[MissChaucer]

Hi
i have very recently had to ask myself exactly the same question regarding paying for transferring the warranty for damp proofing, maybe from the same people as i am in Exeter When you look at the warranty do they "make good" afterwards ? The problem also is that if you do any other work on the walls it can be the reason/excuse for the damproofing failing .... even using the wrong paint. i would say if you were going to sell the house then it maybe worthwhile but if you are there for the forseeable future then carry on as you are and do the job properly. I can't quite understand that if one uses a DPC why not use a Gypsum plaster as the walls are no longer breathable anyway. The damp proof company that DP'd my house used a vandex DPM, a breathable base coat plaster and then a gypsum based top coat afterwards and said this was still breathable ... i am not so sure tho' although the individual that came around to look was both very knowledgeable and a really nice helpful chap.

Good luck and thanks for the post as i have the same results from my survey including the now eradicated woodworm
M

 

[masochists-r-us]

In answer to your questions - no, no and no I'm afraid.