External wall insulation - Timber frame

anon_ymous

Reed_Richards said:

If I understand the pictures correctly you have a semi-detached or end-of-terrace house.  The house has had an extension made into the loft so the remaining loft area is at the front of the house (and also a front porch extension).  The exterior gable end wall of the loft is timber and the party wall separating you from next door is made of brick.  The loft has been completely boarded and you say there is 400 mm of insulation under those boards.  How did you verify this?

There is some sort of insulation beyond the boards under the eaves.  Is that some sort of solidified foam?  Do you know how it got there?  

I cannot see any air vents in the loft but there are some vents on the end of the house, two pairs of two that are at, or just above, the ceiling height of your first floor.  Where do these vents emerge on the inside of the house and what are they for?  

Yup, kinda. The whole street has houses like that, so I've got a house next to mine too, which is also a semi detached  house (ie: both sides)

I verified that it's got 400mm of insulation via the EPC report

I had a look at that insulation, and it appears to be just tightly packed insulation material that isn't foam. If it was foam, I'd have expected I wouldn't have been allowed to use get a mortgage on it too. 

I have tried to find those vents inside the house, and I haven't seen any however my *guess* is that they're directly under the room in roof potentially due to the air conditioning unit

Also, I did essentially just move in last month too so I'm still figuring things out with the house 

Reed_Richards

Never trust an EPC report.  Try to see what is under those boards if possible

Is the visible insulation material some sort of fibre them?  A close-up picture might help to identify it.

I think the vents were part of the initial house construction and nothing to do with the air conditioning unit.  It's possible that they are blocked by whatever is under the boards.  This might mean that the loft is not being ventilated as intended and that could lead to condensation issues.

Does the air conditioning unit serve the loft extension or some other part of the house?  Does it heat as well as cool?  Did you get proof that it has planning permission when you bought the house?   

anon_ymous

Reed_Richards said:

Never trust an EPC report.  Try to see what is under those boards if possible

Is the visible insulation material some sort of fibre them?  A close-up picture might help to identify it.

I think the vents were part of the initial house construction and nothing to do with the air conditioning unit.  It's possible that they are blocked by whatever is under the boards.  This might mean that the loft is not being ventilated as intended and that could lead to condensation issues.

Does the air conditioning unit serve the loft extension or some other part of the house?  Does it heat as well as cool?  Did you get proof that it has planning permission when you bought the house?   

I'm not sure what kind of material tbf. Does the following help?

https://imgur.com/a/HYu6gQf

The AC unit, I believe only served the loft or "room in roof" . I say that as there is a big mark right above the bed, where another AC unit would go. The AC in question apparently also doesn't work, and when I saw this house, I saw the same mark before I bought it so I doubt they've taken it with them

Theoretically, a TV could go here too however it doesn't seem like it especially when it's directly above the bed and not in front of it

https://imgur.com/a/rwRLHtC

I do remember seeing planning permission docs but I'll have to dig those out from somewhere. Also, this aside, Home Logic have now quoted me £3500 for EWI

Reed_Richards

At the moment you have (hopefully) 400 mm of fibre insulation above your first floor and the external walls probably have 100 mm of fibre insulation (well that's what my walls have, although my bungalow was built long before your house).  So your existing insulation is to the sides and above; we don't know about your floor.  On the exterior side of your wall insulation is an air-filled cavity that is not well-insulated from the air outside or the air in your loft (which itself has no insulation to the outside).  So your loft is "cold" and the air in the cavity is "cold" and it will remain just as cold if you insulate the exterior walls.  So I really don't think EWI will be effective.

If you want to better-insulate something I would look at that "room-in-roof".  I also advise you to look at how your loft is ventilated.   

  

anon_ymous

Reed_Richards said:

At the moment you have (hopefully) 400 mm of fibre insulation above your first floor and the external walls probably have 100 mm of fibre insulation (well that's what my walls have, although my bungalow was built long before your house).  So your existing insulation is to the sides and above; we don't know about your floor.  On the exterior side of your wall insulation is an air-filled cavity that is not well-insulated from the air outside or the air in your loft (which itself has no insulation to the outside).  So your loft is "cold" and the air in the cavity is "cold" and it will remain just as cold if you insulate the exterior walls.  So I really don't think EWI will be effective.

If you want to better-insulate something I would look at that "room-in-roof".  I also advise you to look at how your loft is ventilated.   

  

Thanks. So I asked the person I bought it from (I have his phone number), the following:

"Here's a question. Do you know what those two vents on the side of the house are for? I can't see any inside the house"

They replied with 

"Yes  I do, when the extension was put on the first thing they did was to put 2 steel girders though the side of the house, if you open the loft door  and look directly under the door  you can see one."

Reed_Richards

So does your vendor mean that they took out some bricks to insert the steel girders then, rather than replace the bricks, they covered the holes (which they may or may not have bothered to fill) with those vent covers (which may or may not give access to the cavity)?

anon_ymous

Reed_Richards said:

So does your vendor mean that they took out some bricks to insert the steel girders then, rather than replace the bricks, they covered the holes (which they may or may not have bothered to fill) with those vent covers (which may or may not give access to the cavity)?

Hey

So here's more

Me: Thanks, so not a cavity per se which confused me as it's a timber frame house

However probably just to let the loft "breathe" I guess

Vendor: It's plaster then timber frame with insulation then brick,  the girders sit on the brick.

You could take the covers off bu you then see the edge of  the girders as they come right to the edge , the other end sits on the cavity wall between yours and next door, but only on your side of the cavity,  again you can see that in the loft if you look to the left.

Me: Thanks. I wasn't even aware there were any cavity walls tbf!

Vendor: Only on the  adjoining property
________________________

So, it seems that's why the EPCs of the street seem a bit weird in terms of not being standard. Like it seems next door has a cavity wall that sits directly onto ours, but the rest is timber. Weird 

Reed_Richards

I'm by no means an expert on timber frame construction but my understanding is that the brick is just cladding, it's not intended to give any structural strength.  Therefore the steel girders should not be resting on it. Hopefully they are not but it just looks that way.

I think the fact that your party wall is a brick-built cavity wall may be something to do with fire regulations.   

anon_ymous

Reed_Richards said:

I'm by no means an expert on timber frame construction but my understanding is that the brick is just cladding, it's not intended to give any structural strength.  Therefore the steel girders should not be resting on it. Hopefully they are not but it just looks that way.

I think the fact that your party wall is a brick-built cavity wall may be something to do with fire regulations.   

That would explain the weird layout of the street when it comes to different EPCs lol

Reed_Richards

Did you have a survey done before you bought the house or just rely on whatever your mortgage lenders did?  Those fake vents make me nervous.