I am just about to buy a house that has solid brick walls. I will be having
a DPC installed (probably injection?) but the surveyor said something about
recommending I had the walls insulated, and mentioned dry lining.
Is this the best way to go about it, or are there easier/better ways, and if
dry lining is the way to go, how?
I am probably going to have to DIY it, and many other things, as finding the
huge deposit necessary these days have left me pretty much skint - Expect
more posts from me on here as I find other bits wrong with the house!
Does the house actually need the walls insulated ? Is it a prerequisite
requirement of the mortgage (which I doubt) or a surveyors expert opinion
that in order to reduce energy costs, reduce heat loss, etc the walls is may
be desirable to have the walls insulated?. In otherwords it's just a
suggestion. Or do you need to insulate the walls because of structural
problems with the house?
Just out of curiosity why are you having the DPC installed? I presume it
already has one? The reason I ask is that when we bought our 1900 house (
... and I can hear the yawns from the regular contributors/readers that yet
again I've mentioned I have a 1900 house ... ) it was a requirement of the
mortgage that DPC to the rear of the property be injected. The problem was
actually due to the house having settled and the concrete footpath around
the house was higher then the DPC (due to the house settling) and damp was
able to bridge the DPC ... as the footpaths were all been removed and
re-laid I pointed this out and I never did have to have the DPC injected.
Lowering the footpaths solved the problem ... obviously this may not be the
answer in your case.
phone, the basic jist was that there were no structural problems, but it
will be very expensive to heat, it is an end terrace so 3 walls out of the 4
as I am aware, I know a previous owner who confirmed that when he moved out
in the 70's that the house had never had a DPC.
Not sure whether the mortgage company will insist on a DPC, but obviously it
is something I will be getting done anyway, and while I am about it I may as
well do the insulation work.
A house of that era will normally have a slate damp proof course.
It may have got buried by raising of ground levels.
Also, there probably won't be a damp proof course under a hearth,
as the heat from the fire keeps that dry, except you probably
haven't had a fire in it for decades;-)
I wouldn't waste any money on damp treatment until you've been
there for a while and seen what, if any, genuine damp issues you
have. Rising damp is the most unlikely of the lot. Installing a
DPC where you have damp which isn't actually rising damp will
usually make it worse.
[email address is not usable -- followup in the newsgroup]
Yeah, there's also the BRE tests where they stood all sorts of designs
of walls in water for years, and none of them got rising damp. And the
case where a dpc injection company injected masses of walls with
nothing but water, and had no complaints. Theres lots of info on this
topic out there.
If they were using modern plasticised mortar and quality engineering
bricks, they wouldn't.
If they had a 17th century brick an lime mortar, that would be a
Why don't you take it to the standards people, and tell them that every
house with a DPC doesn't need one.
Why not earth your house up above DPC and revel in the dry interiors.
And a lot of it is applied out of context or is plain lies.
If brickwork doesn't absorb water, how come frost spalls it?
How come it sucks mortar dry when you lay bricks?
How come you get efflorescence?
I am not saying that its the be all and end all, or that companies
aren't cowboys, but that doesn't invalidate the whole concept.
Rising damp definitely occurs from wet ground to masonry, and probably
extends 4-6" above the water table. Noticeably. Enough to rot timber in
contact with it and blow plaster over it. I know, because I had it. vOn
the wall that WASN't injected.
they used all sorts of bricks and mortars, including lime. None
suffered rising damp.
why would I get involved in that? wacky suggestion.
it might get damp. A dpc isnt going to make any difference to such
it does absorb water
_that_ may not, but theres enough information that does. You just dont
What you had is damp near ground level. Lots of houses have had this.
To then claim that a large proportion of cases of damp near the ground
are due to rising damp is a simple non-sequitor.
Why dont you go do some reading.
I think "none" is slightly overstating it, iirc there were one or two
test walls with a very soft brick and high sand lime mortar where they
did observe it.
The general observation that rising damp is rare and hugely over
diagnosed is fair though.
are you telling us you have enough experience to know the mixes used
were too sandy in a signifcant percentage of houses?
which tells us nothing. We know mortar fails in the end, that doesnt
tell us if the mix was too high in sand
Thing about lime mortar is its both soft and very slow setting, which
both hinder construction speed. Mixing it too sandy only makes it
worse, slowing the build project even further. I cant see many
builders doing that to save a fiver in lime.
I dont have enough experience personally, but have heard from folk
that do that its not a problem in practice.
I've not come across that. The main issues with pozzolan are:
1. it needs to be mixed dry and kept dry until use. This is not very
compatible with the usual site practice at the time of mixing all the
mortar required on site in one go at the beginning.
2. It needs to be ground very fine to work. Thats not something one
can do on site, so its more cost to put it in
3. It needs prolonged mixing times in the dry phase to work, again
translating to a lot more labour, bearing in mind there were no
electric cement mixers
4. It sets as quickly as cement, resulting in wastage.
In short, pozzolan wasnt normally used in housebuilding for all these
reasons. I couldnt possibly rule it out from all builds, but there
were several practical reasons to not use it.
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