approx cost to correctly insulate roof

[superdon]

Ok, so standard mid terrace house with a room in the loft so no access to the insulation from the house.

Roof being stripped and refurbed.

I think there is some.insulation in there, but doubt its up to spec. What approx cost of materials and labour to add insulation when the roof off?

Cheers

 

[s60tsy]

Ask whoever is doing the roof, they will be able to do it cheapest as they are doing the reroof, they won't want to provide scaffolding and access/time for someone else to nip up while the roof is off

 

[noseall]

Ok, so standard mid terrace house with a room in the loft so no access to the insulation from the house.

Roof being stripped and refurbed.

I think there is some.insulation in there, but doubt its up to spec. What approx cost of materials and labour to add insulation when the roof off?

Cheers

How do you know that it is feasible to actually insulate from above given that the house is terraced?

Are you or the roofers aware of the complexities of this type of insulating/venting detail?

Are you aware that it is B'regs relevant?

You may be able to get say 50mm of celotex between rafters whilst leaving a 25-50mm air gap above, but this won't be nearly enough. The remainder, i.e. 70mm underdraw would need to be fixed from inside. I'm pretty sure the roofers are not interested in this.

 

[noseall]

P.S. a loft conversion insulation detail can take a gang a couple of days or more to install (correctly) and costs upwards of £1000.

 

[superdon]

Cheers. We don't know what's up there and won't until the tiles are off. We aren't going to be able to reach reg levels of insulation, I know that much. We are just going to improve what we have and do what we can.

Surely adding something between the rafters is better than doing nothing?

 

[Toproofer]

Cheers. We don't know what's up there and won't until the tiles are off. We aren't going to be able to reach reg levels of insulation, I know that much. We are just going to improve what we have and do what we can.

Surely adding something between the rafters is better than doing nothing?

👍 All u can do is upgrade something is better than nothing, even building control officer will say this as for cost afew 8x4 insulation sheets plus afew hours to install,it's not a big job to do when roof is off,roofers who are doing job will tackle it

 

[superdon]

Cheers. We don't know what's up there and won't until the tiles are off. We aren't going to be able to reach reg levels of insulation, I know that much. We are just going to improve what we have and do what we can.

Surely adding something between the rafters is better than doing nothing?

👍 All u can do is upgrade something is better than nothing, even building control officer will say this as for cost afew 8x4 insulation sheets plus afew hours to install,it's not a big job to do when roof is off,roofers who are doing job will tackle it

Thanks. That's what I wanted to hear. So I can get an idea of materials cost, how many sheets of insulation would I need approx? I believe its around 55 square m, with a couple of chimneys, a velux and a former.

 

[noseall]

Surely adding something between the rafters is better than doing nothing?

As long as you do it correctly, i.e. with the correct venting etc.

How are you going to deal with the VCL etc?

 

[superdon]

Where does the VCL go?

How would you go about this? Like I say we don't want any disruption to the room itself and want to do all of this from above while the roofs off. Having said that part of the ceiling in the room has got to come down soon, as it needs replacing after a leak from the chimney. So that will provide some access from underneath but not to the sides.

Is it possible to simply put some insulation between the father's from above, then replace the rooms ceiling with an insulated board and then skim over?

 

[Toproofer]

Whats VCL?

Your loft room will have cupboards at the Eve's or access into roof void ? If so only need to insulate up from there the other bit will be with rock wool or similar? I did a terrace house and the 40mm boards came in about £200 think roof area was 25m2 per side, the breathable felt I used was Procter roof shield felt. Afterwards if u want u could board ceiling with insulated boards no probs, I'm surprised roofers havnt priced the insulation in there quote??

 

[superdon]

There's no access to the roof voids

The roofer didn't include in the quote as he wanted to see what was there first

So around £200 for matrierials. How's about labour costs to put it in? I presume you used 40mm as that was the biggest that coukd be fitted? Should I just ask them to put in as thick as possible?

 

[noseall]

Where does the VCL go?

The VCL (vapour control layer) is fitted to the warm side of the insulation, i.e. internally.

I think your idea that you can do this successfully from inside and without risk of future problems, is becoming less likely.

I'm surprised roofers havnt priced the insulation in there quote??

I'm surprised you know so little about vaulted roof insulation details.

 

[superdon]

Where does the VCL go?

The VCL (vapour control layer) is fitted to the warm side of the insulation, i.e. internally.

I think your idea that you can do this successfully from inside and without risk of future problems, is becoming less likely.

I'm surprised roofers havnt priced the insulation in there quote??

I'm surprised you know so little about vaulted roof insulation details.

So, do you suggest not bothering with altering or adding any insulation?

 

[noseall]

So, do you suggest not bothering with altering or adding any insulation?

Surely adding something between the rafters is better than doing nothing?

As long as you do it correctly, i.e. with the correct venting etc.

All humans produce water vapour, some more than others. It is a lifestyle thing. You may not have any issues at present, or you may change the way you live and have a bathroom in the loft, or start drying clothes on all the radiators, or start a hobby boiling lots of food, or you may have some ultra air tight widows fitted etc.

The thing is, there is a robust way of insulating and venting and this often gets overlooked. A lot of roofers believe that because they are fitting breather membrane, then this is a magical panacea for all things condensation and all worries are over. Not true.

This is why we have designers.

 

[Toproofer]

Where does the VCL go?

The VCL (vapour control layer) is fitted to the warm side of the insulation, i.e. internally.

I think your idea that you can do this successfully from inside and without risk of future problems, is becoming less likely.

I'm surprised roofers havnt priced the insulation in there quote??

I'm surprised you know so little about vaulted roof insulation details.

It's impossible to fit that vapour barrier on a re roof it's all well and good on a new build or extension

So put nothing in at all then?? Building control will love that,you are making it more complicated than it is?? Upgrading insulation is all you can do or put nothing in. Been roofing for 25 years and no enough about roofing cheers, never had any call backs for problems😉