DIY Insulation 1950s house

deniseq

Myself and sister, are planning on insulating the attic of my 1950s house. From what I can see there is very little insulation at joist level, plan there is to cover with 200mm earthwool (btw this is 3 for 2 in B&Q at moment, other threads have advised that is cheaper in building providers not true at present I've shopped around). My question is it necessary to insulate the roof joists I was think of stapling something like superquilt to the rafters? In the past I've had to leave the attic hatch open to warm up the attic to keep the tank from freezing, so this would be the reason for insulating the ceiling joists to keep attic space warm as there is no felt just roof tiles.

I've read many posts on insulating attics, and can’t find the answer that matches my particular situation. Superquilt is expensive and don't want to buy if its not warranted. any advise would be greatly appreciated.

BryanF

deniseq wrote: »

1. My question is it necessary to insulate the roof joists
2. I was think of stapling something like superquilt to the rafters?
3. In the past I've had to leave the attic hatch open to warm up the attic to keep the tank from freezing,
4. so this would be the reason for insulating the ceiling joists to keep attic space warm as there is no felt just roof tiles.
5. Superquilt is expensive and don't want to buy if its not warranted. any advise would be greatly appreciated.

some post! Denise your working yourself up over nothing..

1. do you live in the attic? do you want to heat x number of m3 (possibly 1/4 of your floor area) for no reason? if the answer is 'no' then insulate on the ceiling joists!
2. for get it! it's not going to do you any good. any insulation you install should have the correct certificate for the correct purpose which this foil does not. and (as per answer 1.) forget insulating the rafters unless you intend to live in your attic!
3. that's because you haven't insulated your attic, water pipes or your water tank! consider a PIR type insulation for the tank and pipes
4. I don't understand this? why is not having any felt a reason for insulation at the rafters? especially with the foil crap!
5. don't buy it. buy the recycled plastic bottle stuff, that you discussed above, its cheap and does the job.

on superquilt their clever fookers, they have

BRE testing, Moisture Performance of SuperQuilt BRE Report number
223653.1 BRE was commissioned by YBS Insulation to assess the vapour
transmission of SuperQuilt. The vapour permeability was used to calculate
the vapour resistance (Rv) of the material. The Rv was measured as
390.6MNs/g.

http://www.insulationdistributors.ie/downloads/thermal/ybs/Superquilt.pdf
this means it has moisture performance, BUT NOT thermal performance

so to a lay person this reads like a great product, then you read on and see it gives a great U-value BUT NO WHERE does it give the products thermal resistance, which is the first thing you will see on any normal insulation product.
my advice stay well clear of any such product, with out the correct BBA or IAB certificates and also anyone who suggests you use them, unless they can back up there case sufficiently with the correct certs

dathi

the recommended min amount of insulation is 300mm so if there is 100mm there already then adding the 200mm b andq is fine personally i would go the whole hog and put two layers of 200mm over what ever is there. do not block up the eaves with the insulation as you need ventilation handy way of preventing this is to use old election posters cut them 100mm wider than the space of your rafter come in 50mm and score one side with stanly knife fold up the 50mm on both sides so you have a u shaped board the with of space of rafters and 50 mm high slid it down to the eaves and fill under with the insulation. as to your water tank do not put any insulation under the water tank .but use ridged insulation like kingspan around the tank and over it . you can cut it to shape with saw or bread knife if you have no saw and tape the corners with duck tape. as to the multifoil on the rafters there is no point if you have put the insulation on the joists there will be no heat in the atic for the multifoil to reflect. that and the fact that most of them have no certs to back up the claims they make

deniseq

Thanks so for the advise, I'll will fire ahead with the earthwool and get the tanks and pipes insulated