Questions regarding insulation and old Victorian homes

[boilernoob]

Hi guys,

I've had a company contact me regarding insulating my home for free with a government grant, which is a 1900 stone-built victorian terrace (similar to pic below)

Now correct me if I'm wrong, but I thought that since these homes have uneven stones, the cavity cannot fill properly and also can be counter-productive as it can cause damp/sweating?

What do you advice?

 

[Hugh Jaleak]

Probably the same Muppets that rang me, I am still waiting though for the Surveyor they promised to send to turn up. My house was built in 1894, and has 9" solid walls. Really want to know where they plan on putting this 'free' insulation....

 

[boilernoob]

Sorry to hear that Hugh. So since arranging for solid wall insulation, other than the surveyor not getting in touch, would you say it's otherwise a good thing? What about damp issues?

 

[dishman]

You probably have two options in that situation, with it being solid wall construction.

Interior insulation, where your internal walls are lined with a thermal material. Downside is you loose some internal space and probably any Victorian architectural room detail. Plus side is that Victorian rooms are usually very large (so you only loose a bit of room space)... so this may be a better option. Any architectural details can be retained/preserved underneath but also replicated in the "new room".

Second option is the much more drastic exterior insulation, which is like a giant tea cosy for your house. More expensive (although you say it is free). The major downside with this is that if it is a Victorian terrace as you say...it will completely change the look of the property. You will loose a lot of exterior architectural detail as far as I can see. If it is in a terrace as in the image above, it will also stand out like a sore thumb (it will actually stand proud from the rest of the terrace due to the new thicker exterior wall). As many people buy houses like that for their original external features, depending on area, it may affect the properties desirability. Some people do not care about looks though....

Internal insulation may be the way to go if you have a choice.

Here is a good summary:


http://www.superhomes.org.uk/resources/insulating-a-solid-wall/

 

[boilernoob]

thank you very much for your help dishman.

i don't understand how it would change the external looks of my house as the guy said he will drill holes into the wall and then pump/inject the insulation into the wall and should cause no damage (other than the drilled holes) or serious change to the exterior of the property.

Is he doing this correctly?

PS: He said he is qualified BUFCA installer (http://www.bufca.co.uk/)

 

[dishman]

Sorry, I think misunderstood/mis-read. I thought you were saying it is a solid wall construction.

Did he inspect the property in person? Or just talk on the phone? If it is a Victorian property it may not have a cavity at all. Just a thick wall. Hence there is no actual cavity to fill. That is why alternative ways to insulate have to be thought of.

There are a lot of victorian properties that do have cavities. However it was not standard practice in those days. Do you know for sure you actually have a cavity. If you post images of the brick work pattern we may be able to tell. If not then you need to get a survey to assess if it does, or ask a neighbour as they may have already checked.

 

[KenGMac]

boilernoob, Hi.

Cavity wall insulation, which appears to be what this COWBOY, and then sum? is apparently offering you.

Cavity wall insulation is designed to improve the thermal Insulation of CAVITY BRICK WORK WALLS, not the Masonry that you appear to have.

Cavity brick insulation is to fill the cavity between the outer leaf and inner leaf of a cavity BRICK wall.

As far as your Property is concerned, your external walls are made of large masonry blocks, thickness of these blocks is highly variable, anything between 400. MM to well over one meter thick whereas a brick wall is average two leaves that are 50. MM thick.

in your wall there is an inner plaster layer that is wooden studs fixed to the outer Masonry and support a lath and Plaster inner surface.

Clearly is there is no cavity to fill, it will no be a possibility to fill the air gap between the back of the lath and Plaster and the masonry wall, this will simply attract dampness to adversely severely damage the internal plaster surfaces, If however in the future, someone devises a method of installing this type of insulation I for one would be very interested!

As for the so called " External Insulation" route ? ? ?

Ask your installer to get planning permission to do this, on a property like yours, NO CHANCE!

Suggest you give this Guy the run around, as above.

As an aside, this is really scary.

There are loads of job ads where the poster is asking for applicants as Loft and Wall Surveyors with a view to installing insulation, this has been on-going for more than two / three years the kicker is that the Adverts state clearly the there is Quote, " NO EXPERIENCE NECESSARY"
This states it all?

Hope this assists, get shot of this Cowboy.

Cheers.

Ken.

 

[Hugh Jaleak]

Boilernoob, my post was somewhat tongue in cheek. My house (and the rest of the terrace) are of solid wall construction, therefore there is no cavity to insulate! I am waiting for their surveyor to prove me wrong, as they are adamant I can have some 'free' cavity wall insulation!

 

[boilernoob]

So what you guys are saying is that moron is actually doing cavity wall insulation on a solid wall property?? But if that is the case, the what is this site about then? http://www.bufca.co.uk/home-owners/hard-to-heat-properties/???

@ dishman - he inspected the property and said it can be done
Not sure what you mean by brick work pattern, but what I can tell you is that the property is stone on the exterior, but brick walls on the interior? Does that tell you anything?

@ KenGMac - Hi mate. Thanks for the warning. My property was built in 1900 and is uneven stone on the outside and brick on inside. The exterior looks more like the 1st pic below and the interior wall after removing plaster looks like 2nd pic below.

@ Hugh - Ahh right, lol. One thing I don't understand is how is he getting any money from government if he is going around putting the wrong type of insulation?

 

[Hugh Jaleak]

That is why I am eagerly awaiting a surveyor, (it is I think a different company though) to tell me how they intend to provide this cavity wall insulation. (Have told them on several occasions I have a solid wall but they know best....)

I'd also check out the product they intend to use. There were issue in this area during the late 70's/early 80's with a foam type insulation that was causing allergy problems for residents. The installation company conveniently then went bust.... (Once the stuff is in it's not easy to get out either!)

 

[dishman]

As I said, contrary to many peoples expectation, not all victorian properties are solid walls. Ken G Mac may be wrong.

There was no standard building practice at that time. So you may indeed have a cavity. It may not be very large, but you may have one. The outer course may be stone and in inner leaf (wall) looks to be normal brick.

There can be issues of cavity wall insulation exacerbating damp (I said exacerbating...not causing). This can be because you are retrofitting a product on to an older building. So, for example it may not properly fill the cavity (if there is debris in there). This can lead to cold spots on the wall which will be more prone to getting damp by condensation forming on them (condensation and moisture from your living habits in the house). This maybe more likley to happen with a small cavity where debris can get trapped or stuck.

There is the opinion that a cavity is there to be a cavity and it should not be filled. If you fill a cavity it could bridge the outside wall with the inner wall and could transfer moisture. This would be an example of cavity wall insulation causing damp. Modern materials are meant to mitigate the chances of this happening.

Not so sure about this next one, just what I have heard/read: There is also the question of cavity wall ties (they are metal bars/rods which connect the two walls. I am not sure what they would be made out of in victorian times. But they may be at the end of their life and rusting. You may want to look at getting new cavity wall ties before getting insulation. I think it is easier to do before insulation is installed (i remember reading about it somewhere). Again I do not know what kind of ties were used on victorian buildings...if at all? Can anyone correct me on this? Is this somthing to consider or not?

So....there are pros and cons and you will always get a variety of opinion. My 1930s semi had it's cavity walls insulated in the 1970s with rockwool. Apparently there were a lot of issues at the time, but my house does not seem to have any damp issues at all.

Going back to my first point about insulation exacerbating damp. This can be because there is no longer enough ventilation and controlled drafts in a house. Not many people realise that the more they insulate and make a house airtight, the more moisture they trap in the house. This in turn shows up as damp. Not cause by the insulation, but the lack of ventilation. So to combat this you may need to install extractor fans in the kitchen and bathroom, and learn how to ventilate your house more effectively.

There are many companies doing cavity wall insualtion at the moment. It can be a bit like upvc sales at their wost and you end up with a cowboy doing it. Maybe exploring it via your energy company and that may ensure you are using a repuatable company....I don't know....anyone else have thoughts on this?

 

[boilernoob]

Thanks dishman. I think you've answered my question mate. I really do need to think about this before going ahead. My home is very drafty and hardly warms up. It's like there are gaps where air is escaping as I can always feel the cold coming from somewhere.

 

[boilernoob]

Hello again everyone,

sorry to trouble you, but I have a little bit more info regarding the type of insulation...

Below is the pic of the insulation that they want to inject...it melts into the wall???

 

[dishman]

That looks like spray on insulation. how are they going to retrofit that on the wall?!?! It is not injected at all.

The only place I can see them doing that on your property is in the roof.

Unless your walls are down to the bare brick inside? In which case they maybe lining the walls like the internal insulation example I gave you on that link, which means you lose some room space. But spray on insulation?!

Everytime I have read about this stuff on these forums it has always got bad press. Once it is sprayed on, it is impossible to get off apparently.

Others with more experience in this field should be able to give a more qualified answer.

 

[boilernoob]

He told me that they drill small holes in the external wall and then use a machine to pump this into wall with pressure.

The question is mate, is this stuff any good? Can it cause any damp issues?