EIFS cladding systems 3

[hokie66]

To save googling for those who don't know, EIFS means Exterior Insulation and Finish System. It is a relatively new facade material in Australia. I know there have been lots of leakage problems in the US and some other countries with these systems. Apparently, common practice has been to directly apply the system to the structural wall, so the waterproofing is a barrier approach. Anyone have experience with making this into a drained wall by creating a cavity by battening over the sarking before the polystyrene sheets are installed?

 

[SkiisAndBikes]

EIFS systems are often used in Canada, not without problems in the past due to the use of non-drained systems. There has been a great deal of investigation and research in this area over the last 10 years. I will look for some background info over the weekend and post. In most areas of Canada, non-drained systems are not insurable from a design perspective, i.e. the architects association requires drained systems be specified, otherwise your insurance coverage for that project is void. There have been too many problems specifying face sealed systems.

A typical drainage layer consists of a polypropylene mesh attached to sheathing/backing substrate and air barrier. The insulation is applied over the drainage mat.

 

[JedClampett]

You might be better off posting this in an Architectural Forum. EIFS is a bad word in the states. INHO, it was marketed as a less expensive insulation/finish system than stucco or siding and insulation. Part of its cost advantage was that it could be applied by relatively unskilled (non-union) labor. But when the stuff started failing, the manufacturers blamed it on the unskilled applicators. And now the lawyers are involved.
I've run into contractors who won't touch the stuff. It's not a bad product, although it has its quirks. If they're not familiar with it in your area, do you want to be the one experimenting?

 

[Ron]

hokie66...the barrier systems just don't work. Even the drained systems are a bit problematic because of a lack understanding of the need for sealing penetrations, floor line jointing, window flashings, and other details.

I have experience with DryVit and Sto systems. The Sto liquid applied barrier seems to be pretty good, but depends on proper application (as always).

I would not specify either (or any other EIFS for that matter). I'm just not a fan and have done too many water intrusion failure investigations to have any level of comfort that they will work for the long term.

 

[hokie66]

I'm not a fan either...thus my question for you folks. From what I read, EIFS in the states is normally applied by gluing it to the sheathing. The way it is being used here, it is connected strictly by screwing to the studs, with big washers on the outside of the styrofoam. In New Zealand, they allow it, but only as a drained system.

This is one of the companies who are marketing the system here. A lot of it is being used, so maybe a lot of work for water intrusion investigators in years to come.

http://www.masterwall.com.au/system_index.htm

 

[Ron]

hokie66...sounds like a lot of the crap that the US purveyors use.

You're right...lots of business in the future for the failures.

Do I need to open an office in Oz?<g>

 

[hokie66]

You would like it here. Maybe in Cairns, where it is hot with high winds, lots of rain, high humidity. Sound like your kind of place?

 

[Ron]

You're right...my kind of weather! Have a niece who married a cherry farmer in Oz. They gave it up after a few years and came to the states.

If I make it there, you have to buy the first beer!

 

[beton1]

Before building my house, I did a lot of research into this system and reviewed it on work sites (other homes being built). The problem is installation and lack of review or understanding. The finished product looks great; however, there are inherent problems. For example, wood sheathing is not recommended (by me anyhow, among others) as the backing. I used cementboard. Further, there are tactics that some contractors use. You may think you are getting a layer (a base coat to be a final line of defence before styrofoam is installed). What I observed is that the styrofoam is embedded into this coat. Not the same to me. I had joints taped (with mesh and base coat), then a base coat, and then the styrofoam embedded. Some systems now use a blue-green coat applied to the substrate, then the styrofoam is embedded. The colour difference also prevents this short-cut. Once the styrofoam is installed, I observed many installers only applying mesh at corners and windows/doors. Somehow this is not right, there will eventually be a crack at styrofoam joints. I don't care if they say the stucco is 'rubber' based and can stretch and bridge etc. I insisted on mesh (fibreglass) over all of it. The cost, an extra $500 or so. Bottom line, you get what you pay for, and then you still have to keep your eye on the details. Generally, in the Toronto area, it costs $7 to $8 per square foot plus mouldings.

 

[beton1]

Most systems now, as mentioned, require the drainage layer, before styrofoam. Personally, I like stone... but my wife... you know how that arguement will end.

 

[hokie66]

I think the commonality in the systems used in Australia with those you refer to in North America is limited to the material itself, and of course the variability in workmanship. Houses here are not common sheathed throughout...only enough sheathing is used for the actual bracing required. So we have sarking applied directly to the studs, then the cladding system, be it brick, EIFS, or whatever. So the EIFS is not adhered to sheathing, it is screw fixed into the studs. In my opinion, the system could work satisfactorily if a cavity is provided. Then the performance depends primarily on the window flashings, etc., and that is where the rub comes in.

 

[PSlem]

Another problem in SE US is termites used the insulation at ground level as a highway to the upper wood.

 

[SkiisAndBikes]

The Canadian Mortgage and Housing Corporation (CMHC) has produced a "Best Practice Guide" for EIFS systems in Canada. It contains a wealth of information, details, specifications, etc.... based upon research by some very well known building scientists and partly in response to the errors in the past. It is independent of the various manufacturers. One word of caution, the guide has been prepared for a Canadian climate and may not be entirely suitable for different climactic regions. You can try googling to get more info or they have an order line for the binder 1-800-668-2642.

 

[Ron]

If flexible sarking is used, it creates problems under wind loads. The deflection can debond the foam if adhesive applied, but not as much of a problem for mechanical attachment.

I agree that "the Devil's in the details". Flashing, sealants, sealant joints, floor line joints, control joints...all can be problematic.

 

[notlondon]

EIFS costs $8 per square foot in Toronto plus mouldings.
I'm paying $14 per square foot which includes the mouldings and all materials. House has 2000 square feet of wall spacr. EIFS is adhered to brick with cement, then fiber glass mest, base coat and mouldings for windows. Finally finish coat. Can anyone advise where I can get this work done for $8 per square foot. Thanks.

 

[hokie66]

In Toronto, apparently.