The Damp Proof Course debate - do i need one in my 1870 stone terrace??

[Lalala]

Hi there,

I have noticed some opposing schools of thought on damp proof courses, especially for old properties. Some consider them to stop the building breathing and eventually make damp issues worse, for others there is no question they will help.
I have just bought an old stone end terrace with floors at ground level that bounce like a trampoline. There is damp/wetness rotting some of the joists that have been looked at so far.

The floor is about level or maybe only slightly higher than the pavement outside. I didnt check when in there yet.
There is a leaky gutter on one side that has been going on for 3 years at least (google maps). There is a cellar under one of the two living rooms, suspended wooden floor under the other.

There may well be other leaks, ingress etc, as I havent even got the keys yet.

I had someone from a damp proof company (I know) have a look and recommend and quote for damp proof course plus replacing joists, boards etc.

There is a lot of stuff that contradicts this on the net. Some of it is by middle class people who throw loads of money at lime plaster, clay paint, ventilation systems etc just so they can say they have done it 'right' perhaps. I dont have endless money, I am on a searching for joists on facebook marketplace kind of budget, so obvs dont want to pay £2200 for a dpc on top of the other work, if not all that helpful. But I cant pay and spend years trying to get it sorted the most 'correct' way as I may not be in this house for that many years and I need it liveinable pretty quickly and sorted the most inexpensive way possible.

Soz for the long message. Any thoughts and expertise most interestedly and gratefully received.

 

[Mr Chibs]

Wait until you get the keys, look around, take lots of photos and then ask.

Gutters leaking won't help and may be a contributing factor, but it's a stab in the dark.

There's loads of remedial ways of addressing damp, some cheaper than others.

Take it you won't be using Barrow & Fall on top of your middle class lime render.

Hahaha.



As for the DPC, have you seen what your neighbours have... or chatted to them?

 

[Deleted member 174758]

Round here people tend to go for injection DPC (stone area). It lasts 20 to 30 years and has the advantage that it is relatively cheap and can be a DIY job (you hire the injector machine, and an SDS, and buy the fluid and long 10mm SDS bits). The plaster on the inside has to come off and it may be better replacing plaster below the dado with a good waterproof render if only because it'll dry out faster after a flood. On the other hand lime plaster takes months to dry out and provides a nice home of dry rot to spread behind.

 

[Lalala]

Thanks both

Sorry i dont know how to reply individually.

Thanks MR Chibs. As for the Barrow and Fall. Only if its going cheap on marketplace lol. Not spoken to neighbours yet but will do. I guess I assume most people just go with what is advised such as DPC and dont question eveything and skimp on everything like me lol.

Job and Knock thats interesting about the dry rot risk with lime plaster! Crikey - and the time taken to set. Thanks for the info about a diy dpc!! Will defo get onto that. The plaster needs to come off anyway. there isnt an actual flood risk, I dont think, as its near top of a hill.
What about this thing of sealants and waterproof renders holding moisture IN then?? A load of crap in your book then I take it. Do de-humidifiers come into play on the regular where you are then? Wondering if one could assist at least to start with.

 

[flameport]

Any thoughts

Property has been there for 150 years without a DPC.
Why does it suddenly need one now?

There are always causes for damp, water ingress and so on.
Such as:

The floor is about level or maybe only slightly higher than the pavement outside.
There is a leaky gutter
There may well be other leaks, ingress etc,

Fix those.

 

[Lalala]

Thanks Flameport. Yes thats why I mentioned those aspects as some agree that you need to find those causes of the damp and get rid of that. That makes sense to me as it has been neglected in terms of guttering, heating ventilation and who knows what else.
I just dont want to be idealistic either though and find I dont get it sorted. The ground floor appears to need a lot of joists replacing through rot but as you say. How recently this occured and how long the house went on fine when looked after properly before that, is anyones guess.

I cant do a lot about the floor level if thats an issue though - can I?
Thanks

 

[Lalala]

Also finding some controversy now about whether you can do injectable dpc on stone.

 

[Mr Chibs]

It's possible once you've fixed the outstanding issues, you won't need to address the DPC/damp.

Start with the easy/cheap bits.

 

[Lalala]

Thanks a lot Mr chibs. YEs I think thats what I will do. Sounds sensible as well as appealing to my financial tightness. I wonder about the floor level thing. I should have said - it is public pavement on two sides and a half, so I cant dig or anything externally. Need to check the level to be sure though once Ive got the keys.

Thanks all so much for your help! I imagine I will be visiting this site on the regular going forward.

 

[bernardgreen]

Good advice here

The Society for the Protection of Ancient Buildings
https://www.spab.org.uk/

and papers from a conference can be found here

https://historicengland.org.uk/advi...-masonry-decay-and-sustainability-conference/

 

[Lalala]

Ah brilliant links BernardGreen! Especially the conference! Thanks so much

 

[Deleted member 174758]

What about this thing of sealants and waterproof renders holding moisture IN then?? A load of crap in your book then I take it. Do de-humidifiers come into play on the regular where you are then? Wondering if one could assist at least to start with.

It depends on the kind of wall. There are people in this valley and the next valley who have been flooded 3 or 4 times in the last 20 years and who are frankly fed up with "experts" telling them that they shouldn't have DPMs and they must retain lime plaster, and so on. Nice if you have the money, a nightmare to deal with if you get flooded. A good friend of mine has had 3 floods since 2001: the first flood came up through the ground, through the suspended timber floor and went 3 feet up the wall in his living room. That took 6 months with the plaster hacked off and dehumidifiers going full blast to dry out before he could get it replastered. When it was redone, he paid extra to have the walls rendered. Next time he got flooded (this time through the front door) it took 3 weeks after the water had gone down before he could replace the floorboards and redecorate. Last time he ripped the timber flooring out and had a concrete floor (with a DPM) installed throughout his ground floor, like some of his neighbours had done. (Incidentally rot in joist ends is generally a good indicator of a wall which has damp problems)

A stone wall with a rubble infill (mostly quite a bit older than your house) is a nightmare to deal with because the rubble infill absorbs DPC fluid like a sponge, so that's a no-no for them and all you can do is render or just lime plaster and live with the damp. It is true that renders do hold water in the wall - but a but the issue is how far up a wall will the moisture travel? With buildings from the 1870s onwards you have a chance of cavity walls and can treat the buildings in the same way as you would a more modern building (my current house is 1880 and has a non-standard cavity with stone outer leaf and brick inner leaf). If you have a DPM at floor level and a moisture resistant render going up to mid wall level it is unlikely that the damp can penetrate far enough up the wall to make any difference to you. I was told by the "old hands" in the building trade round here to get my roof and troughing sorted then to do the injection job at then end of a dry summer, when the water table was low and the walls had had time to dry out. As to the "it won't make a difference" brigade - well I have had three stone-built houses of my own to counter that argument with, where prior to DPM and rendering the ground floor rooms were **** wet through and afterwards they dried out and weren't damp.

What seems to be forgotten is that these houses were originally built with draughty sash windows and open coal fires which burned 12 to 15 hours a day in winter- so you had air being drawn through the house all the time, which helped to dry them out and keep them dry. Fit modern DG units and central heating and block-up the chimney in such a house (stopping the through flo of air) and the moisture doesn't get drawn out of the house, has nowhere to go and you get damp ground floor rooms. I've had properties where the damp went 5 to 6 feet up the wall because the land at one side of the house was much higher, and so was the wter table in the wetter mionths. So I feel that the biggest issue with old houses is that people fail to understand the need to ventilate them adequately - that certainly makes PIV units worth looking into as well.

I know writing that puts me at odds with a lot of people, but I wonder how many of them actually have to live with their decisions day in and day out?

Oh, and sorry but 1870s isn't an ancient building, so I think a lot of that any "historical building" type of argument when applied to a relatively modern building of little or no architectural merit (as is the case for many terrace houses after 50 to 60 years of people ripping out ranges, sash windows and traditional doors) is just so much tosh (that's not a go at you Bernard, but a comment about some of the utter carp which gets talked about older houses by "learned bodies").

 

[bernardgreen]

Oh, and sorry but 1870s isn't an ancient building, so I think a lot of that any "historical building" type of argument when applied to a relatively modern building of little or no archtectural merit (as is the case for many terrace houses after 50 to 60 years of people ripping out ranges, sash windows and traditional doors) is just so much tosh (that's not a go at you Bernard, but a comment about some of the utter carp which gets talked about older houses by "learned bodies").

No problem, I agree that many so called "learned bodies" do not understand how to live in and maintain an old style building.

 

[Lalala]

Thanks so much JobandKnock for your replay and I am sorry you and your friends have had such issues going on.
I really appreciate the realism of your response as I dont want to go the snob route and not actually have a comfortable home any time soon!

I was thinking that calling this house ancient might be stretch too lol, though i guess some practices didnt change much for a long time.

Im seeing a lot about ventilation and I am very big on it already and may kick off with addressing the obvious ingress issues, ensuring ventilation - possibly through use of machines if needed, which arent as expensive as I thought - but with a view to having no problems with having a dpc and associated works if things dont look like they are going and staying in the right direction.

I expect this may be the type of cavity wall you describe too, with a layer of brick internally. That point about doing it when the house is at its driest sounds like a plan if I go that way too.
I work in a different sector completely but the same controversies between the conceptual and detached views of the academic and the living day to day reality of certain decisions is similar there too. As well as each case being potentially different, which is also the case with properties it seems. To understand what applies in what context and will actually be of real world benefit in the long run etc. Anyhow, I much appreciate you sharing your real world experience.
I have plenty to consider to inform my way forward now - and will defo do a dpc myself if I need one now that Ive seen how easy they are! What a rip off!

 

[Deleted member 174758]

What makes it worse is that a lot of the work I have done is on listed buildings (refurbs and repurposing ) where we generally do things "the right way" (i.e. using methods and materials mandated by the architect, building engineer and conservation officer) and then the people taking on the building afterwards have to live with the issues (as seen when we have to do post hand-over snagging - this happens a lot more often than it should IMHO).

As it happens injected DPC is pretty easy to do and fairly cheap if you DIY, and it often works quite well. There are some gotchas, but I'm sure you'll have found them already.