building a new house this year

Buildright said:
Conormark,

Ya Edwardian is nice, hers me reminiscing about the grand 'ole days of the empire, servants in the basement and potties under the beds, ah it brings a tear to my monocle. I think the institute of architects needs to take a good look at itself, seeing how much the people of this country despise contemporary architectural design in favour of 'ye olde worlde styles'.

Back to the present, the insulation boards should be taped, with the outer layer having staggered joints. Low conductivity wall ties. The inner wall build first, insulation fitted tight to about a foot below the dpc level. At the windows you have to use a fire rated cavity closer. This gives 100 insulation rather than the 25mm used in standard cavity closing.

I'm finding it difficult to recommend window companies at the mo. Standards of installation need to be improved. Installers love that expandable foam stuff. Its useless for airtightnes. For sash windows there is a company called wood.... they are a good window for heritage buildings.

Ancon two part wall tie has been approved by my structural engineer.
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Thanks Buildright!
 
conormark said:
My friend who built the 200mm cavity sourced suitable wall ties but he has warned me they are approx 1.5times the price of a standard tie. Not sure where he purchased them but will check it out and make sure they're certified.
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thanks, could you post the names and product on here...... id appreciate that!!
 
Conormark / Buildright etc
I have been following this tread with interest. I am close to beginning my own home in the near future and was contemplating a 200mm cavity also. I have looked at 200 cavity with full fill blown bead insulation using Teplo wall ties. I'd be interested in any opinions on this build up and mainly the use of full fill bead?

Regards,
Bov2
 
bov2 said:
Conormark / Buildright etc
I have been following this tread with interest. I am close to beginning my own home in the near future and was contemplating a 200mm cavity also. I have looked at 200 cavity with full fill blown bead insulation using Teplo wall ties. I'd be interested in any opinions on this build up and mainly the use of full fill bead?

Regards,
Bov2
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Hi Bov2, I am am still trying to decide on exactly what composition of insulation I will use in the cavities; one of my friends who has used 200mm cavities has been living in his house for approx 1.5yrs and the last time I spoke with him he was very satisfied with the performance of the dwelling and had used limited fuel in that time. From memory, he uses a 60mm Kingspan board (standard, not the Kooltherm higher-spec product) and has filled the remainder of the cavity with beads. I'm still wrecking his head with questions so any info I get I will post. Hard to beat 1st hand real-life experiences.

Without going into any science, 200mm cavities have got to pay dividends in terms of energy efficiency. I mean look at the sheer physical amouunt of insulation you can get into that size of a cavity. Maybe someone else has a different angle on it and I would be delighted to hear the pro's and con's. I would have thought if your house is insulated to an excellent standard then maybe the heat source you choose is not just as critical.

Someone mentioned to me recently however that when you use natural stone, you should retain a cavity space which may not be as achievable with the use of beads. I'm no expert by any means but maybe somone else could jump in here and confirm if this is accurate or not?

I personally have only heard positive stories regarding the use of beads.

Another thing to realise is that 200mm cavities leave us with thicker walls which I am hoping will produce good effect in my Edwardian style house.

i checked out the Teplo wall ties you have mentioned and their website says that they're currently being tested for BBA certificatrion in the UK. Are there any issues with using these in ROI in terms of compliance with building regs? Thanks for letting us know about the Teplo ties! I must get a quote for my house from them.
 
conormark said:
i checked out the Teplo wall ties you have mentioned and their website says that they're currently being tested for BBA certificatrion in the UK. Are there any issues with using these in ROI in terms of compliance with building regs? Thanks for letting us know about the Teplo ties! I must get a quote for my house from them.
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conor...

no certification = do not use....

im in the process of checking if the ties you linked to have certification.... they DO appear to be a much better product... the teplo ties is nothing more that a rebar!!...
 
sydthebeat said:
conor...

no certification = do not use....

im in the process of checking if the ties you linked to have certification.... they DO appear to be a much better product... the teplo ties is nothing more that a rebar!!...
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yes, on irst impressions I thought the Teplo tie looked somewhat unusual for a wall-tie. Please let us know re certification on the other ties. :)
 
bov2 said:
Conormark / Buildright etc
I have been following this tread with interest. I am close to beginning my own home in the near future and was contemplating a 200mm cavity also. I have looked at 200 cavity with full fill blown bead insulation using Teplo wall ties. I'd be interested in any opinions on this build up and mainly the use of full fill bead?

Regards,
Bov2
Click to expand...

Hi Bov2, since I posted my last thread, I have looked at another possible way of doing the cavity; instead of making the cavity 200mm, I could make it the standard 100mm wide and use a higher, more dense grade of insulation board (such as Kingspan's 'Kooltherm' product) and fill the rest of the cavity with beads. The 'Kooltherm' is more expensive however but I would save on the wall ties and less beads. I could also build the cavity 150mm and use the same combination. The reason for my change in thought, although undecided, is that my architect has designed part of my house with the inner leaf walls built 'on their flat' i.e. 215mm leaving the overall wall section much thicker. I am conerrned this would impact too much on daylight penetration. The reason I have been given for the 215mm wall is due to the 'span' of the rooms i.e. they are around 5500mm but I want to check this out for myself as I have not come across this before in dwellings. Maybe it is common and hopefully someone out there could advise or has come across this before?
 
The big assumption there is that you trust that the Kingspan Kooltherm's u valus for hot box test are similar to simulated installed u values. Well let me tell you that they are not even close, in fact the stated o.27 u values are closer 0.46 in practice due to thermal bridging and looping. Its one thing fitting insulation for a lab, quite another doing it on site.
 
Would the addition of the beads to the Kooltherm insulation bring the combined U-Value up to the level required?
I'm hoping to build this year also and am very interested in this topic.
From what I can see adding the beads to the kooltherm is maybe a achievable belt and braces approach, whilst also minimising complications at construction....then again this is my first build so am open to correction.
Boots
 
Buildright said:
The big assumption there is that you trust that the Kingspan Kooltherm's u valus for hot box test are similar to simulated installed u values. Well let me tell you that they are not even close, in fact the stated o.27 u values are closer 0.46 in practice due to thermal bridging and looping. Its one thing fitting insulation for a lab, quite another doing it on site.
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that's a good point Buildright and is being realistic and practical about the issue. since I last posted, I have been giving the insulated dry-lining plasterboard some consideration (Kingspan K18, 50mm made up of 37.5mm insulation and 12.5mm plasterboard). maybe using it in conjunction with 60mm Kooltherm (K8, in the cavity) and no beads. would be interested to hear any comments on this approach. I have spoken to other home owners who have built in the past 2 years and used this type of a approach and have been very happy with it.
 
boots said:
Would the addition of the beads to the Kooltherm insulation bring the combined U-Value up to the level required?
I'm hoping to build this year also and am very interested in this topic.
From what I can see adding the beads to the kooltherm is maybe a achievable belt and braces approach, whilst also minimising complications at construction....then again this is my first build so am open to correction.
Boots
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not sure Boots...i didnt really check much out on the u-values on the beads as of yet. maybe someone else can jump in here? :)
 
I'll also be building this autumn and I'm a bit confused too. I was advised that insulation beading was a very good way of reducing drafts within the cavity, but does anyone know if this creates an issue in terms of providing effective weep holes?

At the moment, I'm leaning towards Aeroboard's Aeromark Platinum, 140mm thick to suit a 150mm cavity. I'm also probably going to use Qwik-Fix glass fibre wall ties. They're cheaper than Teplo-Ties and certified to BS EN 845-1.

[broken link removed]
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This should give me walls of normal enough thickness, a U-value of 0.20 W/m2k and effective weep holes. Can anyone punch holes in this for me?
 
Hi all.

i too, hope to build soon, im just wondering where ye are getting your information, is it from website or have ye approached someone to design and propose insulation for ye?

earlier in the thread, people were talking about air changes, and my question is; if a 2 leaf cavity wall fixed with mortar in all the joints, is then plastered externally and internally, a roof is felted and slated, windows & doors fixed by a joinery, and all samll builders ope are sealed with mastic, where or how does the air changes acur, or why to we need a specialist to do the above, i know cold briding is a different topic!

thanks
 
@ house

The fundamental reason for a cavity wall is not insulation, it's drainage. Bricks, mortar and render are semi-permeable so it's inevitable with our construction methods that some moisture will creep past the first line of defence, i.e. the rainscreen, veneer, outer leaf wall...whatever you want to call it.

Expansion gaps are sealed with mastic, but you still have to install weep holes at regular intervals to allow the moisture to drain out of the cavity. This also facilitates air exchange.

Having an air gap is regarded by many as healthy in a cavity wall because it provides a chamber to effect pressure equalisation across the exterior leaf to counteract forces that drive moisture through the building envelope. Air movement also helps dry the wall components.

This is all great, but I'm confused why some engineers prefer cavity closers and bead insulation which both restrict this airflow. Has anyone got any ideas on this?
 
HI,

Dose any one know what the builing cost are now per sq foot?
 
Huge variation out there depending on spec of finish, geographical location, method of building, procurement route choosen you can go as low as €65/sqft and as high as you want a good spec carried out by a builder €120/sqft basic builders finish €75/80/sqft

www.selfbuildardmore.blogspot.com
 
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