can anyone help me i cold and damp problem.

[cornishtiger]

hi there i live in a end terrace house and the end wall of my house makes the house very cold and damp. that much my son don't like spending anytime in his bedroom because of it .what can i do about it .its a old house and it don't have a cavity wall .can i put on the outside some kind of insulation then batten it off then slate the whole end wall.i've seen other house with slates on the side of there house and it made me think to do that but insulate it first .or am i barking up the wrong tree with that one.lol.if anyone can advise me on whot to do i would be very gratefull so would my son..thank you .

 

[mointainwalker]

Sounds like the right thing to do subject to using the right covering for local conditions and any possible planning restrictions. What's the current outside surface of the wall ?

 

[cornishtiger]

Sounds like the right thing to do subject to using the right covering for local conditions and any possible planning restrictions. What's the current outside surface of the wall ?

its just got painted rendered wall that it.when you say planning do i need permition to do it?

 

[mointainwalker]

There are two points here, neither of which i am certain about.

Your local council may have regulations about keeping houses looking "in keeping" or similar so no one paints theirs fluorescent yellow.

It;s unlikely that what you propose would be affected by that but there might be a 'preference" for slates rather than , say, larch shingles as the covering.

The other is that I have read on this forum that under Building Regs, if you renew more than 25% of the surface of the walls of a house, then it all has to be re-newed and to latest insulation specification.

If you are in a terrace, this might catch you and I'm sure that you would not be allowed to cover the whole house in slates.

I am a little hazy on this point so if anyone else could give absolute clarity, it would be useful.

 

[cornishtiger]

thanks for your advice i only want to cover the end wall tho. ill have to speck to my local council.someone told me about putting a insulation up then covering in mesh(eml)i think then rendering over the top of it ,i think that is what they were talking about have you heard of this?

 

[mointainwalker]

putting a insulation up then covering in mesh

Yes. That would be the standard way to insulate the walls externally, but that is not particularly common in the UK I believe. Expanded polystyrene is the usual insulation for this. Here in France they normally use a nylon scrim mesh instead of the eml.

One of my friends is having this done at the momemt and , talking to him yesterday he gave me the following info.

He is having 12 cm ( new regs here) and bought poly blocks from a company called Sto. This cost him E 11/m2 ( GBP 9.50 ). This company has developed a new type of render which can be applied directly to the blocks without the mesh and is currently the only company to have CTSB ( equivalent to BRE ) certification for this procedure.

The above price was direct from the company as his total order was about GBP 3 K. The per m2 price from a builder's merchant was about 50% more.



You need to think about everything that might need altering/be affected by the extra thickness ( prob 8-10 cm I guess ), like window-cills and surrounds, guttering and down-pipes.

If you go down that route please let us know about the quotes as I would be interested to get an idea of costs in the UK.

 

[cornishtiger]

no problem mate ill keep you informed thanks for your help

 

[joe-90]

Why not just use insulated plasterboard inside? Cheap, effective and quick.

 

[cornishtiger]

i did think about it but it would mean doing all down stair hall.srairs,kitchen,landing,bedrooms and the loft will still be damp and a cold spot and i would have to get the whole lot plastered and painted.i thought the slate thing might work out cheaper in the long run and less disruptive to the house.but this is only my thought iam on here for as much help with this problem as i can get and am open for all suggestion.

 

[JohnD]

I have seen it done it Switzerland, they used a white foam with very fine bubbles (didn't look like polystyrene) and a rigid cement board bolted over, which they rendered. I think they used stainless studs to fix the foam boards, then an extra thin nut on the end of the stud to hold the cement board.

BTW if you are cladding a wall, the ground-floor part has to be with something strong enough to be knocked and bumped without damage. My house has slate cladding on one wall with shiplap on the ground floor; the swiss ones has stone cladding (ugh) on the ground-floor part

 

[^woody^]

You will need to have a really good think about whether this external insulation will solve your problem, without just moving it elsewhere

You say you have a cold and damp problem, but is that a cold and condensation problem, a [penetrating] damp problem causing condensation, or a damp problem causing coldness?

You don't mention whether the bedroom is actually heated, or what if any heating the property has

External insulation still leaves you with a cold wall, and can still cause condensation issues on the insulated wall, between the wall and the insulation (leading to proper dampness) or condensation on other surfaces

If you have a condensation problem, then you need to realise that and deal with it. And then it may be that this removes the dampness and may well improve the environment in the bedroom

I would forget external insulation for the moment and think about what problem you are trying to resolve. Otherwise you may be heading for an expensive mistake which does not solve anything

 

[JohnD]

Good point

I accept that a non-cavity wall can get very cold, especially if it is a corner room with two external walls.

But in terms of low cost/high return, start by making sure you do not have a condensation problem (most often caused by people draping wet washing around the house or on radiators); make sure the ceiling is very well insulated (loft rolls are subsidised and very cheap. Ten inches is the modern standard); and verify that the radiator is of adequate size. If this room is colder than others in the house, you probably need to increase the heat output relative to the others. This can be done by fitting a larger radiator, and/or fitting Thermostatic radiator valves, and/or balancing the radiators so that other rooms heat up slower.

for condensation and damp, see //www.diynot.com/wiki/building:condensation_in_houses

if all else fails, you could add a small electric heater, but remember electricity costs about twice as much as gas.

 

[mointainwalker]

External insulation still leaves you with a cold wall

Far too broad a statement. The insulation will significantly diminish heat-loss through the wall and almost eliminate the extra heat-loss by wind blowing across the surface.

This will increase the internal wall temperature by a measurable amount.

Woody is right however that we have all ingnored the damp issue and whether it is condensation or penetrating damp.

 

[^woody^]

External insulation still leaves you with a cold wall

Far too broad a statement. The insulation will significantly diminish heat-loss through the wall and almost eliminate the extra heat-loss by wind blowing across the surface.

This will increase the internal wall temperature by a measurable amount.

The OP will still have at least 225mm of solid masonry on the room side

Now, this will take a [relatively] long time to heat up before it goes above the dew point and then it will need to be maintained at a given temperature to avoid cooling to a point where air then condenses on it.

In practice, and especially for a bedroom, the heating will not be used enough to maintain a steady temperature of the masonry, and so it is highly likely that there will be cooling of the wall which will go on to cause condensation issues.

If addition if the OP just wants to insulate one wall then any other external wall in the room will potential create or add to a condensation issue - especially at external corners

External insulation has to be specifically considered along with other factors, and not in isolation, and particularly not in part

 

[mointainwalker]

Now, this will take a [relatively] long time to heat up before it goes above the dew point

Woody

You are making assumptions that you cannot possibly justify.

In the previous mail you asked rightly whether it is condensation or penetrating damp and what type of heating there is. You are now assuming it is condensation without any answers to those questions.

For it to be condensation , how are you aware of inside/outside temperatures and humidity in this specific case ? Can you enlighten us ?
Is it an app that you get with 5,000 posts ?

Yes, raising the temperature of this one wall may give rise to other (smaller) problems like condensation in other areas but if they allow the room to be used more then that is worthwhile ( IMO ) and then those problems can be tackled in order of priority.

Having said that, it is v important to ascertain what can be done with lower-cost measures which requires confirmation from the OP about a) heating b) type of damp