airtightness: Timber frame sole plate solution

[Mark Siddall]

Some Swedish research on airtightness in timber frame construction notes the fact that a cellular rubber (or I'm guessing an EPDM gasket) between the sole plate and a concrete floor provides an excellent seal. Much better than all other commonly used options. Mastic sealants were not examined (unless this is "asphalt felt celllgummi"). The poorest detail was found to allow 30-40 times as much leakage as the best one. The results are listed below.
A= profiled cellular rubber, (<0.2 m3/(h.@50Pa))
B= extruded polystyrene strip (<0.4 m3/(h.@50Pa))
C= asphalt felt celllgummi [sic] (17 m3/(h.@50Pa))

Does anyone know of a manufacture/ distributor of this type of product? Or the extruded polystyrene strip for that matter.

Cheers,
Mark

[Nick Grant]

Hi Mark

Are the units correct for a linear leak? m3/m/h??

Did the try Compriband type tape? Perhaps that is the asphalt celligummi?

[Mark Siddall]

Hi Nick,
I reckon that asphalt celligummi may be bitumenous felt but don't know for sure.... This particular study did not seem to examine tape. Another Swedish study that I have examined airtightness detailing to windows. ;-)

Here tapes achieved an air leakage of zero, zip, nada, nothing, nill. Quite remarkable really. To acheive this attention was paid to the corners as you might expect. In the same lab, and I assume the same standards of care, no other solution examined achieved this kind of result. Given the rather suprising success of tape the study did examine instances where corners were left incomplete. The air leakage rose to 0.93 m3/(h.@50Pa) with a hole in one corner, two corners 1.74 m3/(h.@50Pa) and three corners 2.45 m3/(h.@50Pa)

As for the units. I must admit that the paper is not clear on the units. It merely uses the term "air leakage." EN 13829 states that the units for the air leakage coefficient is m3/(h.@nPa), where n is the pressure difference (which I know from the paper)...... so I'll change the units on my post (thanks for identifying that.)

Mark

[Nick Grant]

Interesting.

Re units I was thinking in terms of leak per metre of join being more useful than usual m/h through an area of surface. If they are quoting standard m/h then need to know the total area of the test box relative to the length of leak or have I misunderstood this?

[Mark Siddall]

Nick,
I can see what you getting at. But would the linear measure really be of value?
I'm just reading these results for the relative value. Detail X is better than Y, Y is worse then Z. It's the "has greater success" info that is really the most valuable in reality. The more that you can design out site error through specifying the right products/ technology the greater the chance of achieving the performance targets (one would hope!).

Mark

[Dave Howorth]

Interesting serendipity. I was just reading some product brochures about EPDM gaskets used between concrete floor and timber floor plate and they referred to some Swedish research ...

http://www.conservationtechnology.com/building_gaskets.html
http://www.conservationtechnology.com/documents/WeathersealHandbook0705.pdf

Do you have a reference for the Swedish research?

I found the company via a thread either here or on another forum. Conservation Technology have quite a few PDF summaries of parts of their website that I found interesting. Some of them mention European origins for their products. I'd be interested to know if there's a similar European company (UK would be too much to hope for).

Cheers, Dave

PS I'm with Nick that the units should be a linear measure but I do accept that best reliable performance is the goal.

[Mark Siddall]

Hi dave,
That's just the kind of thing. Does anyone know of of UK distributor? (Project and client don't have time for along wait.) I'll try to dig out the references when I get a mo.

Mark

[Nick Grant]

Mark

Linear or on area but with the area and length of detail under test stated. I'm assuming that the linear join is the only leak and that the rest of the test rig is 100% airtight. If not - eg a real building, then linear might be hard to determine.

To apply the knowledge application need to convert back to air changes or m/h for a given structure with a known sole plate length.

Nick

[Mark Siddall]

Nick,
Given the data that is presented in the paper (just a conference paper not a full technical review) only a relative understanding is possible. On this basis m3/(h. @50Pa) will have to do! As a range of solutions were test using the same rig (not a house) and the same building elements thus the datum remains the same in all cases. Yes, I assume 100% airtightness at all details that are not under review……
I’m not trying to justify someone else’s work. I’m just telling you what they presented!

Moving on:
Trelleborg is where Conservation Technologies get there cellular EPDM structural gaskets. Here’s some links to the Trelleborg info:
http://www.trelleborg.com/en/Sealing-Profiles/Products/
http://www.trelleborg.com/en/Sealing-Profiles/Products/Agriculture/
http://www.trelleborg.com/en/Sealing-Profiles/Solutions/Other-Building/

Catalogue:
http://www.trelleborg.com/upload/SealingProfiles/Files/Catalogue_Other%20Building%20Applications_2008.pdf

Not sure whether they have any meaningful distribution in the UK at the moment (though there is UK contact which I’m chasing for info)

Mark

[Mark Siddall]

Swedish Papers:
http://www.sp.se/sv/units/energy/eti/Documents/SP%20RAPP%202004_22.pdf
http://www.sp.se/sv/units/energy/eti/Documents/Slutversion%20Word%20rev%20juni%20laguppl.pdf

Mark

[Andy Simmonds]

This kit for quick airtight service penetrations looks interesting - anyone used it?
http://www.airtightkit.co.uk/

[Mark Bennett]

Moving on:
Trelleborg is where Conservation Technologies get there cellular EPDM structural gaskets. Here’s some links to the Trelleborg info:
http://www.trelleborg.com/en/Sealing-Profiles/Products/
http://www.trelleborg.com/en/Sealing-Profiles/Products/Agriculture/
http://www.trelleborg.com/en/Sealing-Profiles/Solutions/Other-Building/

Catalogue:
http://www.trelleborg.com/upload/SealingProfiles/Files/Catalogue_Other%20Building%20Applications_2008.pdf

Not sure whether they have any meaningful distribution in the UK at the moment (though there is UK contact which I’m chasing for info)

Mark

If you do reach their UK contact then you might want to suggest that their strapline in another brochure is perhaps badly translated:

"Solutions that Seal, Damp and Protect."
 from: http://www.trelleborg.com/upload/SealingProfiles/Catalogues/Standard%20products_EN_web.pdf

[Rob Rickey]

The Canadians were using split surgical tubing in the 70s - in two rows stapled to the underside of the wall plate. They still promote a sill gasket, as here (polyethylene foam tape) http://oee.nrcan.gc.ca/residential/personal/new-home-improvement/choosing/insulation-sealing/materials/khi-airbarrier.cfm?attr=4