Best block construction methods

... well if it falls down on my head it'll be an issue yes!! At the moment the walls are the least of my problems - getting out of the ground is the issue :(

My architect and structural engineer will both stand over it, and yes it is being bespoke designed by the structural engineer. The final U-value estimate is .11 so that's good. My foreman has a personal bug-bear over badly fitted insulation board and so I hope all will be fitted perfectly on his watch. Also using 2*80 kingspan boards means that we can lap the joins and so further minimise leakage

will keep the forums updated over the next 12 months and will come back to this thread at the time of cavity design for additional detail ... I know there is a debate about laying the inner leaf on the flat for the concrete floor upstairs ... that was a while ago - but that's what the structural guys are there to do ... God Bless the professionals when things get complicated :)
 
trying to lap the joints on 2 x 80mm boards is going to be very very difficult with the increased frequency of wall ties.
You will probably have a wall tie on every block course around opes, this means you may only be able to incorporate 225 height boards at these points.

When calculating u values i hope your engineer was including for the increased frequency of wall ties, plus the u value calculator doesnt include a default for gaps in the boards (incorrectly imo)

personally, IMHO whilst you may not achieve a similar u value, you would probably get a much better performing wall with a pump in insulation such as rockwool energy saver.
 
sydthebeat said:
personally, IMHO whilst you may not achieve a similar u value, you would probably get a much better performing wall with a pump in insulation such as rockwool energy saver.
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Whats that 'rockwool energy saver' product then? I'm familiar with in-fill cavity bead insulation - take your point about wall tie freq. around the opes - architect is a pro-board man rather than in-fill so that's why we had gone down that route to get to the .11u value but as that figure comes from Kingspan,I am guessing its just a straight calculation based on block and boards without any of the 'negatives' u mention

when would it be blown in - when wall is fully completed 2 storeys or as you go? Blown from the top or in along courses? I'd be a bit nervous about having no air cavity tho - what about transfer of damp/wet from the external leaf? You suggest anywhere I can get a quote for the 'rockwool energy saver' product u mention so I can compare values and costs?
 
[broken link removed]

http://www.rockwool.co.uk/graphics/RW-GB-implementation/datasheets/EnergySaver.pdf

thats the rockwool energy saver above. Im not in any way associated with this company, i just like the product.

IMHO its a better option that EPS bead insulation as this is pumped in under pressure so theres a minimal chance of sagging compared to beads.

As i say, it wont give you as good a 'theoritical' u value as the baord insulation, but IMO it will actually give you a better performing structure.

Board insulation has issues such as 'thermal looping', incorrect jointing (poor workmanship), gaps at corners, reduction of performance through diffusion of gases...
 
First time poster!! so go easy!!. I have settled on a quinn lite 150mm inner leaf, 2no. 60mm xtraterm or kingspan boards, a 40mm air gap, (this gives a 160mm cavity in total) and a 100mm outer leaf dense block.
What kind of u-value would this give and would the wall ties need to be more than usual? what do you think of the wall make up?

A lot of people are telling me about the insulation board on the inside of the inner leaf but heard this can create mould, I think it sounds good in theory but has it just become the norm and be out lawed in 5 year when everybody is getting sick due to sick building syndrome
 
hi i built my house using standard block outside leaf-100mm cavity with 60mm kingspan and 100mm quinn lite inner leaf,and the house is very warm(not only my view but every one who calls) and this is without curtains on the windows,.i would use glue instead of mortar if iwas building again as mortar goes off very quick with quinnlite but that wouldhave given me a small promblem with wall ties and levels but a freind who worked in germany told me of longer flexible ties
 
thefisherman said:
hi i built my house using standard block outside leaf-100mm cavity with 60mm kingspan and 100mm quinn lite inner leaf,and the house is very warm(not only my view but every one who calls) and this is without curtains on the windows,.
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Fair enough but at least put it in context and tell us how big it is, how much you spend per year on oil, or gas or solid fuel etc. No one claims that regular build can't be warm, its how much it costs to keep it warm is the issue of course.

Which quinnlite block did you use incidently?
 
house is 2600 square foot.ufh downstairs and rads upstairs(dont really use the rads)heated by thermia diplomat 10kw heat pump.3 girls including baby so plenty of baths and showers and of course plenty of laundry,living in house around 7 weeks.toal esb including standing charge and vat coming in around euro4.20 to 5 euro a day.how much of this is heating and hot water i have not yet had time to find out but hp should cost around8-9hundred a year,the block i used was quinnlite b5.the hp supplies all the heating and hot water for showers baths etc, i have stove in living room but have yet to use it
 
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madbuilder said:
First time poster!! so go easy!!. I have settled on a quinn lite 150mm inner leaf, 2no. 60mm xtraterm or kingspan boards, a 40mm air gap, (this gives a 160mm cavity in total) and a 100mm outer leaf dense block.
What kind of u-value would this give and would the wall ties need to be more than usual? what do you think of the wall make up?

A lot of people are telling me about the insulation board on the inside of the inner leaf but heard this can create mould, I think it sounds good in theory but has it just become the norm and be out lawed in 5 year when everybody is getting sick due to sick building syndrome
Click to expand...

your construction is a good one, but (forgive my prying) how have you 'settled' on this without even knowing its u value???
surely the u value is the singular most important factor in choosing a construction specification.

Any cavity in excess of 110mm needs to have upgraded frequency of wall ties, and i dare say that a 160mm cavity wall would need to be certed by a structural engineer.

Internal thermal linings have not shown to cause interstitial condensation in any calculations i have done to date, so the 'mould' threat is unproven IMO.
 
Can some one run this through the sei calculator to see what u-value it gives please, tried downloading it but can't!! for some reason.

12mm render quinn lite 150mm inner leaf, 2no. 60mm xtraterm or kingspan boards, a 40mm air gap, and a 100mm outer leaf dense block, inside plaster.

Thanks a mill
 
I'm getting a U value of 0.16, pretty good!! Assuming thermal conductivity of Quinn lite block is 0.17W/mk
 
did a uvaluate calc for you and got a u value of 0.15... included all thermal bridges such as wall ties, and even includes normal mortar joints in aac blocks, not thin bed...

[broken link removed]
 
Thanks for the Syd, Is 0.15 close to passive levels? did anybody out there use the quinn block and how did ye plaster it or is it plastered just like a normal dense block?
 
Theres so much more to passive houses than just u values, so i cant comment whether its close to passive levels or not, but it is a good u value.
Have you had a preliminary BER assessment done off the plans??? This will give you the best indication of how energy efficient your dwelling will be....

It does have issues however. Increased cavity needs structural enginner certificaion, partial fill boards are subject to thermal looping (this doesnt effect BER ratings or calcs), if thin bed mortar is used then you need to get your levels correct for lintels cills etc.....
 
I haven't got a ber rating done based on plans, it wasn't a requirment for planning so didn't look into doing it.

As regards the ties how much would they increase by. I have seen this type of construction done but with a standard block and a concrete floor, I think the inside leaf (normal dense block) was even on edge if i remember correctly.
 
im not a structural engineer so i couldnt (wouldnt) specify what the frequency and type of ties to be incorporated.

Are you going to register the house with homebond or premier??? have you contacted them about the extra width cavity??
 
Another form of insulation in a cavity I heard of but I don't think it has been done,

Would it be possible to construct the inside leaf leaving wall ties hanging out, then spray on the inslation to the outside of the inner leaf and then construct the outer leaf of block work.
Advantages: increase air tightness.
Disavantages: you would have to construct inner leaf to first floor level, then spray it, place the concrete floor then construct the outer leaf to first floor level. Then construct inner leaf to roof level spray it and then continue the outer leaf to roof level,

Meaning you would have to bring the spray on insulation contractor on site twice to insulate the house.
 
Sorry Syd, I just posted 1 min after you.

Do you have to get homebond for a one off house, I know builders use it as a selling point when selling the 3 bed semi.
 
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