Single skin, second skin added, insulation query

[kird14]

Hi. This is my first post.

 

We bought a house around 4 years ago. I'm not sure of the exact year it was built but we have records that somebody requested to turn it into a pub in 1905 but was denied permission. A survey estimated it was built between 1875 and 1900. It's detached but very close to one neighbour and all the other houses in the street are terraced.

 

When we had a survey completed, we were told that the house was originally built with a single skin but a second skin was added at a later date, and the surveyor said he'd not seen anything like it before but spotted the same on some other houses nearby. I'm not sure if this is the case for all 4 walls which I need to try and establish.

 

My house is horribly cold. It takes a long time to heat and it doesn't retain the heat. Today for example, its 10 degrees outside and only 12.5 degrees in my living room. In the recent cold weather its been as low as 8 degrees with the heating on.

 

We have loft insulation but our EPC report assumes there is no wall insulation. We have upgraded all windows (except one original sash which has the clingfilm type cover over whilst we get around to ordering some plastic glazing and magnets). We changed the front door which was in poor condition with a hole in it. 

 

Has anybody here seen or owned a house like this? Is it likely we will be able to install cavity wall insulation? I'm not sure how wide any cavity is and whether there are width requirements when considering insulation.

 

Any advice at all is welcome. I work in healthcare but do a bit of DIY and anything I can't do myself I like to research before contacting trades people, hence this post.

 

Thanks!

[Ferdinand]

You are wise to ask all this - good call. My thoughts, which also extend a bit beyond your questions.

 

You can get a rough check on date of build by looking at versions of old maps (various online archives eg https://www.oldmapsonline.org/ or https://maps.nls.uk/os/), and seeing when it first appears. Are there any with a data plaque - it was common in that period?

 

Looking at the pics 1890-1910 seems reasonable. At that date cavities are unlikely, but some were using experimental partial 2" cavities if a well built house. I have a 1910 ish house with some cavities, and well built out of *very* hard bricks. Such cavities will be useless for CWI.

 

I'd suggest drawing a carefully measured inside-outside plan, getting thicknesses of walls - which should tell you something about your wall cavity widths vs standard or measured-in-situ brick sizes. You can also learn by looking at the brick pattern - is it headers or stretchers, where and how mixed? Extra skins may well be stretchers.

 

You could do like a CWI contractor, and drill 12mm holes through mortar joints and insert a camera ("borescope").

 

How does it compare with any other "detached semis" in the area .. eg at the other end of the row? Has it been extended sideways? Roof angles the same? Symmetrical with yours?

 

What is in the planning file? Try a visit to the Council Office to read all of it, or an FOI. What about the BCO file (a bit more difficult to get hold of)?

 

Anything in the Local History Archives at the library?

Can you see anything by reaching into the edges of your loft - either with a head torch perhaps with inspection mirror, or a cable-cam plugged into your mobile phone?

 

Can you get down the gap to the next house? If not, you are somewhat buggered by the lack of access. At least it looks too wide to terminate, through trapping, a tumbling tabbycat.

 

Are they all rendered at the back, or just yours? If it is only a few rendered, it is potentially hiding something.

 

I suggest that you decide on drylining-over-insulation (or not) before pouring your hearts into decoration. Aim for as close as you can get to newbuild u-values.

 

What are your floors? If suspended (ie wood) then consider insulating underneath, and perhaps more on top or just on top if solid - it is a big benefit. My way is 100mm or so rockwool and a staple gun through raising about every 3rd or 4th floorboard, addressing underfloor ventilation  / dampness along the way to protect joists and a membrane on your floor to block air leaks.

 

If you are air-tightening an old house, then ventilation needs as much attention as insulation as you are preventing it "breathing" in the way envisaged.

Wishing you all the best.

Ferdinand

 

 

 

 

[Gone West]

2 hours ago, Ferdinand said:

At that date cavities are unlikely, but some were using experimental partial 2" cavities if a well built house.

That's interesting, as back in the 90s we lived in a 1901 built semi-detached farm workers cottage with a 2" cavity in the main part of the house. There was a solid 9" walled single storey extension at the rear.

[Ferdinand]

3 minutes ago, Gone West said:

That's interesting, as back in the 90s we lived in a 1901 built semi-detached farm workers cottage with a 2" cavity in the main part of the house. There was a solid 9" walled single storey extension at the rear.

 

Various people were playing with them, but afaik not really 'normal' until the 1920s/1930s.

 

IME cavity insulators do not like anything under 50mm.

 

Happy to learn new information from others, of course.

[Gone West]

4 minutes ago, Ferdinand said:

Various people were playing with them, but afaik not really 'normal' until the 1920s/1930s.

IIRC the farm was owned by the Church Commission when we bought the cottage. Something to do with a Canterbury College. They originally built a terrace of three solid walled cottages and then later (1901) two pairs of semis with cavity walls.

[Andehh]

Heating challenges aside, it's a quirky & attractive house! I see the appeal of it, even if an extra £100 a month to run.

 

Start with the easy stuff, 400mm loft insulation minimum. Secondary glazing, even if magnets and acrylic/perspex sheets.

 

Draft proof and cheap thick rugs (eBay has loads) on the ground floor.

 

Any options to fit a wood burner?

 

External insulation, or Insulated plasterboard overboarding on the inside!

[IGP]

I would get a reputable cavity wall insulation installed to come and survey to drill holes and determine the cavity (if any) width. If wide enough, fill with EPS beads, if not leave it. 

I would also explore using EWI along the back and sides of the property and possibly IWI on the front elevation as it does look a nice house. 
 

First though I’d get a cheap thermal imaging camera to identify cold spots to investigate and block up holes with appropriate materials (mortar / expanding foam etc.).

 

Also make sure you’ve got plenty of loft insulation, it’s cheap and super effective. 
 

[kird14]

Thank you @Ferdinand @Andehh and @IGP and I'm sorry for the very late reply to all your helpful advice! 

 

I hope I have answered all your questions/points below:

 

I am pretty sure that I have established that there is only a very small cavity on the wall where the second skin has been added (seen from back garden pic) which wouldn't be enough for any cavity wall insulation based on your advice. The other walls don't seem thick enough for there to be a cavity, or again only a very small one.

 

I applied for a government scheme some time ago where they send somebody out to assess for wall/loft insulation and then assess how much you might need to contribute financially but am still waiting to hear back. From memory, the criteria was council tax band a-c and EPC rating D or below.

 

I am too short even on the top rung of our ladders to see in the loft (haha) but am told there is some insulation, however, not as much as there could be. I was holding out for the gov. scheme but I applied in April and am still waiting for an assessment.

 

Mine appears to be the only one rendered, any ideas what it could be hiding? Am I being naive in hoping it was just for decorative reasons? 

 

We have now ordered some secondary glazing with magnets to fit to our one original window and it should be with us in a couple of weeks.

 

I believe our floors downstairs are solid. I know very little about floors though so not entirely sure what this means for us. We have a beautiful original Minton tiled hallway (as do many around here in Stoke, as it's where they came from) which I would hate to remove. We also have a nice parquet floor in our dining space (other half of the room is the living space and is only carpeted). So really I'm not sure anything could be done flooring wise. 

 

We have a log burner in the living/dining room but it only heats the one room. We can get the room nice and warm but by the morning, it can be as cold as 8° again when it's frosty outside.

Edited February 11 by kird14
Edited to fix typos

[IGP]

Good stuff, 

 

As we're coming out of winter, keep pressing on the loft insulation from the government schemes. However, if you're still not anywhere by September time I'd just pay for it, it will be a few hundred pounds but very much worth it. 

 

How big are your radiators? Single panel? Could be that there is not enough surface area on the radiators to really give enough heat energy off no matter how big your boiler is. Hence always cold!

 

Can you get a few photos of these if you're unsure?

 

 

[kird14]

On 12/02/2024 at 09:16, IGP said:

Good stuff, 

 

As we're coming out of winter, keep pressing on the loft insulation from the government schemes. However, if you're still not anywhere by September time I'd just pay for it, it will be a few hundred pounds but very much worth it. 

 

How big are your radiators? Single panel? Could be that there is not enough surface area on the radiators to really give enough heat energy off no matter how big your boiler is. Hence always cold!

 

Can you get a few photos of these if you're unsure?

 

 

Thanks for your reply.

 

I heard from energy company that "A&M Energy Solutions" will be coming out "soon" to assess our property but after reading their trust pilot reviews I'm mildly concerned.

 

We fitted the secondary glazing to our original sash and it looks much better than the clingfilm type stuff and I think it's warmer on the landing and stairs now too.

 

Radiators in our living/dining room is a strange one! I've attached a pic of our radiator (screenshotted from a video when we sanded our floor back), whilst it's big, it's the only one in the long room (see floorplan). Which baffles me as on an old rightmove pic (attached), there was once a decent sized radiator under the window at the other end too which somebody removed!

[TonyT]

What type of boiler do you have?

hiw long to you have the heating in for ?

what temperature do you try to achieve on a thermostat?

has it ever achieved this temperature?

 

some more info may help diagnose 

[kird14]

@TonyT we have a combi boiler, that much I know. Would any other specific details be helpful?

 

We didn't even have a thermostat when we first moved in! We got one after a couple of years so I can't say during those two years what temp we reached. Since then, we tend to rely on our log burner on cold days so it's hard to say. T&e heating alone takes hours and hours to get even close to feeling warm, so we just stick the fire on. E.g. we can be at 11 degrees and go up half a degree, maybe 1 degree with the heating on for 3 hours+.

 

I have to say I haven't tried leaving it on set to a "low" temp all day/night but I don't hold out much hope that it would work for us. We can get the room to 20 with the log burner in an evening, then in the morning it's back into single figures with the door kept shut all night if it's been a cold night. It just doesn't seem to retain heat. So I imagine the boiler would rarely "click off" and would cost us a fortune when we are both out of the house from 7.30/8 til 5ish.

 

Happy to be told I'm wrong!