insulation for block house

roisincorran

hi. i am building a house direct labour for myself and my son and i need advice on insulation. the shell of the house is up. ie walls, roof, windows and doors. its a double wall of block with a cavity in the middle... house and next step is insulation.. should i pump the walls and with what? and is kingspan plaster board good for the inside? I have bought a H.R.V system so i am going for airtight if possibel. all my windows and doors are triple glazing....any one done an air tight house using cavity walls before??

MicktheMan

roisincorran wrote: »

hi. i am building a house direct labour for myself and my son and i need advice on insulation. the shell of the house is up. ie walls, roof, windows and doors. its a double wall of block with a cavity in the middle... house and next step is insulation.. should i pump the walls and with what? and is kingspan plaster board good for the inside? I have bought a H.R.V system so i am going for airtight if possibel. all my windows and doors are triple glazing....any one done an air tight house using cavity walls before??

:eek::eek::eek:
You've built your walls and you're only wondering about the wall insulation now! .... on an internet forum!!
Who is advising you?
Have you had a prov ber assessment done?
You really need independent professional advice pronto.

Gumbo

roisincorran wrote: »

hi. i am building a house direct labour for myself and my son and i need advice on insulation. the shell of the house is up. ie walls, roof, windows and doors. its a double wall of block with a cavity in the middle... house and next step is insulation.. should i pump the walls and with what? and is kingspan plaster board good for the inside? I have bought a H.R.V system so i am going for airtight if possibel. all my windows and doors are triple glazing....any one done an air tight house using cavity walls before??

You won't be going airtight if your at this stage without proper professional advice. Air tight starts from the ground up!

How are you going to fix the insulation to the walls if you have the 2 layers up already or ami I reading it wrong?

roisincorran

my plan was to plaster the outside block wall. fill the cavity, plaster the inside walls then glue 50mm insulated slabs to them..and use tapes and membranes in roof and ceilings....

seaniefr

I would guess pumping the walls would be the best at this stage but you need to provide protection for mains cables coming from the fuseboard in the house to the meter cabinet. Have you decent insulation under the floors?

Gumbo

roisincorran wrote: »

my plan was to plaster the outside block wall. fill the cavity, plaster the inside walls then glue 50mm insulated slabs to them..and use tapes and membranes in roof and ceilings....

There's a detail in the homebond manual that complies with part L that shows full fill, and an insulation panel on the inside.

But as above, you need to make provisions for the full fill, it's needs to be the required thermal conductivity, along with the correct internal panel to meet the minimum U-value required under part L.

Have you got a provisional BER to confirm if it will meet the regulations?

roisincorran

the main cable is being shielded in copex and the other cables travel through 20mm round pvc conjugate. ya im defo pumping the walls.......and a reenforced radon barrier 75mm kingspan under the floor.and 100mm scree on top...

Gumbo

roisincorran wrote: »

the main cable is being shielded in copex and the other cables travel through 20mm round pvc conjugate. ya im defo pumping the walls.......and a reenforced radon barrier 75mm kingspan under the floor.and 100mm scree on top...

Will 75mm under the floor pass current building regulations?

What's your P/A ratio?

Corkblowin

Watch out for the relationship between the amount of cavity insulation and the internal insulation - theres a danger that the temp of the blockwork could drop to a level that allows mould and/or condensation behind the boards. As your airtighness layer is outside part of your insulation layer (not really a good thing) the RH could rise to a dangerous level at certain times. The HRV could help prevent that, but it will be difficult to get an airtight solution suitable for HRV at this stage - or at least a long-term one! Good luck!

Corkblowin

kceire wrote: »

Will 75mm under the floor pass current building regulations?

Highly unlikely to pass even the 2008 regs - depends on the conductivity of course.

roisincorran

sorry for being ignorant but whats P/A ?

Gumbo

roisincorran wrote: »

sorry for being ignorant but whats P/A ?

Something your BER assessor would have to include in his calculations for floor slab insulation

I'd strongly recommend you get one on board ASAP.

roisincorran

will do thanks. i know a man who does ber. he got me my planning. ill get on the case thanks

Gumbo

roisincorran wrote: »

will do thanks. i know a man who does ber. he got me my planning. ill get on the case thanks

Best off in the long run. You will save multiples of his fee in reduced running costs on your home. Just don't leave it too late, as the BER details are needed by the architect/engineer that is signing off the build in compliance with building and planning regulations.

These are the minimum requirements you must meet and this is only one part of the building regulations. http://www.environ.ie/en/Publications/DevelopmentandHousing/BuildingStandards/FileDownLoad,27316,en.pdf

roisincorran

thanks for all your help. looks like ive got lots of interesting bedtime reading in that 84 page document. its probably high time i read them! nice one

Gumbo

roisincorran wrote: »

thanks for all your help. looks like ive got lots of interesting bedtime reading in that 84 page document. its probably high time i read them! nice one

That's only one. The building regs span A to M.