insulation

irelandhouse

we have an older house, 1977, and are doing the place up.

the house is :
brick, cavity, membrane, timber sheeting, studs, plasterboard.

what we are doing at present is taking down the plasterboards to put the electrics and the plumbings between/through the studs and then slabbing over again - finishing with taping and jointing.

What we are looking for is an insulation solution! - we have looked at two main methods :
1. sheepwool between studs and regular 12.5 slabs
or
2. insulated 12.5mm slabs straight onto studs.

we would also be looking and insulating the attic floor.

does anyone have any suggestions/reccomendations. would be much appriciated.

ircoha

irelandhouse wrote: »

we have an older house, 1977, and are doing the place up.

the house is :
brick, cavity, membrane, timber sheeting, studs, plasterboard.

you sure this is the make up?
what size are the studs?

irelandhouse

the studs are 75x100mm.

the makeup as above is correct. we have cut through on a section to put in french doors and this confirms the make up.

ircoha

irelandhouse wrote: »

the studs are 75x100mm.

the makeup as above is correct. we have cut through on a section to put in french doors and this confirms the make up.

Thanks:, so the bricks are tied to the timber sheeting through the membrane.

There are more informed persons than I on this forum so what follows will hopefully be commented upon by them.

A concern I have is re the membrane and whether it will allow
water vapour to pass through it.

If u use sheeps wool in between the studs u will more than lightly have condensation on the inside of the timber sheeting because the timber will get colder than it is at present, I suspect at present the condensation is on inside of brick and hence not a problem.

The other concern is that 75mm studs will create significant thermal or cold bridging so I would suggest either/some of the following.

Insulate the brick cavity, by pumping it with insulation.

Leave some or all of the air cavity thats between the studs so as if u do get condensation it wont be against the insulation: leave a 25mm air gap

leave the 100mm gap and insulate internally.

Whatever you do try ensure there is NO air movement in the air cavity

irelandhouse

thanks for that irc

we went ripping through some of the walls yest to check a few bits.

the makeup is the brick, air cavity, dpm, timber sheeting, 50x100 studs at 16" centres.

would it make sense to put in a vapor barrier on the studs before putting in the sheep wool instulation would you think ?

I am getting the plans and building details next week and should clear up what the timber sheeting is = its more like a insulated mdf board not 100% of its make up

the sheeps wool seems to have the best uvalue

thanks again

ircoha

irelandhouse wrote: »

thanks for that irc

we went ripping through some of the walls yest to check a few bits.

the makeup is the brick, air cavity, dpm, timber sheeting, 50x100 studs at 16" centres.

would it make sense to put in a vapor barrier on the studs before putting in the sheep wool instulation would you think ?

I am getting the plans and building details next week and should clear up what the timber sheeting is = its more like a insulated mdf board not 100% of its make up

the sheeps wool seems to have the best uvalue

thanks again

the studs were 75mm last night, 50mm tonight... perhaps 25mm tomorrow.:D

2" in 16" is 6.25% cold bridging

If u are adding a vapour barrier it needs to be on the warm side of the ba ba insulation, not on the cold side, otherwise u will trap the moisture on the cold side and get condo.

have a peep here http://www.planningportal.gov.uk/england/professionals/en/1115314255826.html

it was posted elsewhere earlier by someone else
re the sheeps wool seems to have the best uvalue, dont know it is a fn of thickness - it certainly has the best ewe-value:D

irelandhouse

ircoha wrote: »

the studs were 75mm last night, 50mm tonight... perhaps 25mm tomorrow.:D

thanks irc!, i should have stuck to imperial, 2x4's!

2" in 16" is 6.25% cold bridging

this is the 2" of studding from 16", i.e. 14" can only be insulated ?

If u are adding a vapour barrier it needs to be on the warm side of the ba ba insulation, not on the cold side, otherwise u will trap the moisture on the cold side and get condo.

this was only something I thought about earlier while working over in the house, do we need one ? or would it be of any benefit?
you say to install it on the warm side, this would be mean putting it on just before the plasterboard, correct?

have a peep here http://www.planningportal.gov.uk/england/professionals/en/1115314255826.html

the above is extrememly detailed, looking through it now! from alot of sites the sheep jacket seems the best to go. it is suppose to be rigid enough to be able to not sag as insulation rolls would when hanging vertically.

it was posted elsewhere earlier by someone else
re the sheeps wool seems to have the best uvalue, dont know it is a fn of thickness - it certainly has the best ewe-value:D

s

ircoha

IRCOHA:If u are adding a vapour barrier it needs to be on the warm side of the ba ba insulation, not on the cold side, otherwise u will trap the moisture on the cold side and get condo.

OP: this was only something I thought about earlier while working over in the house, do we need one ? or would it be of any benefit?
you say to install it on the warm side, this would be mean putting it on just before the plasterboard, correct?

That is my understanding of it, i would wait and see if anyone else will comment.

jdpl28

Hey, just in regards to vapor barrier, am planning to double the insulation in my attic, but there's no vapor barier currently there. Should I be thinking of installing a vapor barrier below the first layer?

thanks,
J

Mellor

ircoha is correct, the vapour control layer goes to the warm side. It is to control the rate that moisture passes into the structure, this keeps the dew point lower and reduces the chance of interstitial condensation. Strictly speaking a vapour barrier and vapour control layer (vapour check) are not the same thing, the barrier completely prevents moisture passing through.

irelandhouse

thanks for that Mellor


as we have at present :

- brick,
- air cavity,
- membrane,
- timber sheeting(still looking into exactly what the makeup of this is, its like a composite!?!)
- 2x4 studs at 16" centres

what would you think would be the best makeup for a warmer house?

we were looking through alot of info and talking to people who do insulation via rockwool, pumped, beads etc. and I can only get a sales pitch from each.