Category Archives: Advanced

Hot Wire and Knives for Grooving Insulation

Posted by Admin on March 28, 2011 None comments

Windlock is a major supplier of the EIFS industry and has some great tools for contractors. Any serious EIFS contractor will have some sort of hot wire tool to ease the process of installing grooves into the insulation – whether they’re for aesthetic reveals or are required per the manufacturer.

“Hot Knives” are not actually knives – not in the traditional sense anyways. They’re hand-held transformers that pass a current through a wire to heat it to a specific temperature. This heated wire is then able to easily pass through styrofoam, ever so slightly melting is as it passes through. Anyone that has ever tried physically cutting expanded polystyrene knows the mess it can create and how impossible it is to achieve a straight line. With hot wire tools, the mess is avoided and clean lines are easily made. Because they’re hand-held though, some skill is required to actually achieve a straight line.

Hot Knife

Control joints appear commonly between the first and second floor of homes. Residential renovations don’t typically require vertical control joints unless the total area of the wall is greater than a certain square footage. These guides are typically found in the EIFS manufacturer’s specifications.

A lack of control joints between dissimilar substrates is another common cause of EIFS failures. Building materials that expanded and contract at different rates can place stress on even EIFS that has heavy duty mesh. Control joints play a vital, and often overlooked role in residential EIFS renovations.

Inexpensive (and lower quality) hot knives can be found off of places like ebay or craigslist. These less expensive options are great for hobbyists or someone doing a small project, but are definitely not commercial-grade.

View Hotwire on Youtube

You can see more information at: http://www.wind-lock.com/cat-26-1-6/Hot_Knives.htm

EIFS Walls Do Not Require Interior Polyethylene

Posted by Admin on February 14, 2011 None comments

Cliffs: The study points out that wall cavities (between the studs) in EIFS-clad buildings dried faster without the interior 4mil polyethylene barrier than with one.

This is an important point to take a note of, because the majority of homes constructed use a 4mil polyethylene barrier between the drywall and studs based on outdated building practices in warm climates (Toronto is considered a cold climate, further exasperating the problem).

Interior vapor control strategies (vapor barrier/vapor retarders) were introduced to reduce the flow of interior space water vapor moisture into the concealed wall cavity. The original intent was to reduce the inflow of moisture due to moisture generation from the interior of the building. In the 1940’s, American construction materials and wall systems were much different than the ones used today. There has been a lot of speculation and confusion among building envelope practitioners on the use of vapor barriers in constructions, such as the deployment of a sheet of polyethylene or asphalt coated kraft paper for interior vapor control.

Once a home is renovated with EIFS, a water-resistive barrier is typically added to the exterior sheating of the home as part of the full EIF system. This creates a condition where if water gets in the wall cavity (the space between the studs), it will dry slower – increasing the odds that mould or rot can develop. Ideally then, the interior 4mil polyethylene should be removed on homes where EIFS covers the entire exterior surface.

Article: http://www.wconline.com/Articles/Breaking_News/BNP_GUID_9-5-2006_A_10000000000000988992

A study for architects, specifiers and engineers found that in three diverse climates, EIFS with a vapor permeable Class III retarder, kept interior wall cavities warm even in the coldest months, thus preventing the possibility of condensation in the exterior sheathing.

Conducted in partnership with the Oak Ridge National Laboratory, the study measured the moisture performance of four EIFS wall configurations: EIFS with either 2-inch or 4-inch of EPS insulation board and a 4-millimeter polyethylene vapor retarder and EIFS with either 2-inch or 4-inch of EPS insulation board without the polyethylene vapor retarder. Researchers reached their conclusions after evaluating framed walls clad with EIFS without stud cavity insulation in three diverse climates (Boston, Seattle and Minneapolis).

The study’s methodology, approach and observations are outlined in a white paper entitled, “Evaluation of the Moisture Performance of EIFS Walls Without Interior Vapor Barriers” published by Dryvit Systems Inc. To read the white paper, visit http://tinyurl.com/4q88639.

Researchers discovered that for the assemblies and climates tested, EIFS’ monolithic exterior insulation properties eliminated the need for a polyethylene vapor retarder to prevent water condensation in a wall cavity. For the three climates investigated, results of the hygrothermal analysis indicate that use of a vapor permeable (IBC and IRC Class III) retarder on the outside face of the exterior sheathing outperforms the use of polyethylene (IBC and IRC Class I) retarder for diffusion control.

“The results show that the EIFS walls with the Class III vapor retarder and without the 4-mil polyethylene vapor retarder dried faster and maintain balanced conditions throughout the year,” said Bill Preston, Dryvit’s senior engineer/code specialist. “It is also clear that a vapor retarder is not required to prevent water condensation in the wall cavity for the assemblies and climates tested.”

White Paper: http://www.dryvit.com/fileshare/doc/architect/White_Papers_Barriers.pdf

Blueskin on Windows: Why Is It Important

Posted by Admin on October 28, 2009 2 comments

Without a doubt, one of the most common areas of water intrusion on any building is around window openings. Improperly installed windows will allow water to leak in behind claddings and onto framing members, and when mould or rot appears, the cladding is often inaccurately blamed. The fact is that improperly installed windows will cause leakage and water entrapment on the framing of any building, regardless of the cladding.

It has been a point of contention on many projects – commercial and residential – as to who’s responsibility the proper sealing of framing around the windows is. The framers point to the window installers, who point to the cladding guys, who point back at the framing guys, and eventually someone is selected by the general contractor to do the work. A good portion of the time EIFS contractors I have worked with have been the ones selected. In reality, they are probably the most qualified to do this job. There’s an issue with this, but it’s not the topic of this article.

When I ask a home owner – who is replacing windows as well as retrofitting with EIFS – if the window installers have specified blueskin as part of their installation process, I typically get a blank stare. They don’t understand that 20 years ago, most builders had no clue that the window frame needed to be sealed. Some builders today still don’t. But when you’re taking the old windows out and replacing them with energy efficient windows, you have the perfect opportunity to protect your walls from water intrusion, which may lead to mould, which can cost tens of thousands of dollars in repairs. It’s actually something the home owners can do themselves if the window installers refuse or claim it’s “unnecessary”.

So here’s your quick rundown of the blueskin product.

This is what blueskin looks like when you buy it in a store:

Blueskin purchased from hardware store

Blueskin purchased from hardware store

Here’s the primer for the product, which you roll-on just like paint, before applying the blueskin:

Blue Skin Primer

Blue Skin Primer

Blueskin is a “peel and stick” product, meaning you peel the material from the backing and stick it on to your framing, like this:

Peel the blueskin from the backing

Peel the blueskin from the backing

And this is what blueskin looks like installed:

BlueSkin with primer around window opening

BlueSkin with primer around window opening

It’s somewhat reminiscent of wall papering, using much smaller pieces. You want to start in the middle and flatten it outwards, so as to avoid air pockets. Seams need to be overlapped 2″ (typically at corners) and you want to extend it down the face of the substrate (dens-glass-gold in this case, the yellow material) about 4″. The EIFS contractor will then come along, and overlap his weather barrier with the blueskin, entirely sealing your windows from water.

An alternative to BlueSkin (by Bakor corp.) is Soprema’s Sopraseal 1100T – which is essentially the same product. Your local hardware store should carry one or the other.

It is not an expensive step to add, or very complicated, to ensure your project is properly completed. If you’re replacing your windows – make Mike Holmes proud – do it right.

Protected: Stucco Energy Retrofit: Look Rich, Get Rich

Posted by Admin on September 18, 2009 Enter your password to view comments.

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Protected: Alternatives To Achieving Required Building Code Fire Ratings

Posted by Admin on September 13, 2009 Enter your password to view comments.

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