Tag Archives: weather barrier

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of, because the majority of homes constructed use a 4mil polyethylene barrier between the drywall and studs based on outdated building practices in warm climates (Toronto is considered a cold climate, further exasperating the problem).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

Stucco / EIFS Leaky Window Protection

Posted by Admin on February 27, 2010 None comments

Although Exterior Insulation Finish Systems (EIFS – Synthetic Stucco) has bared the brunt of the “leaky window” negative publicity, it is nevertheless a problem that affects all sidings. The problem lies primarily with poor practices regarding the sealing of window frames and tie-ins with the weather barrier.

Sto Corp (an EIFS manufacturer) has put out a document showing how their StoGuard® Tape can be used around any window to assist in this critical detail – with any siding. Following these procedures will help to ensure your home stays protected from moisture and the associated mould and rot issues.

View it at:

http://www.stocorp.com/index.php?/20090714420/Videos-training/sto-videos/menu-id-265.html

Toronto Stucco/EIFS Average Price/Cost

Posted by Admin on January 25, 2010 3 comments

When it comes to attaining a budget price for your home renovation, there are various (dozens, actually) of things that need to be taken into account. Some of them are:

  • Time of year
  • Time frame
  • Size of walls – height
  • Detailing of walls – protrusions, windows, number of surfaces
  • Amount and type of stucco trim/moulding and decor
  • Missing / not-included work items
  • Condition or removal of existing siding
  • Distance of project from contractor

You should be able to budget around $10 per square foot, but realize that this is just an estimate. Getting an actual quote is the best way to find out how much it will truly cost.

As is always possible, you can bargain and haggle the price down, just be aware that whether you are aware of it or not, you are sacrificing quality which will decrease the longevity of your wall system. It’s the author’s opinion that anyone considering renovating or building with EIFS (exterior insulation finish systems) educate themselves on common practices, then pay a little more than what they could get as cheaply as possible.

Look at it like this: If you have 1,500 square feet of wall space that needs to be done, and you might get quotes around $13,000, $15,000 and $19,000. That’s a huge range. More than likely, the $19,000 quote is from a contractor who doesn’t need the extra work but will do it anyways if it’s worth his time, but because they’re overloaded you probably won’t get the attention you need either. At this point, most home owners will go for the $13000 quote, because it is within what they read is “normal” from other home owners, who may or may not (probably the latter) know what they actually got. They think that they are saving $2,000.

But this contractor, unbeknown to the home owner or his competitor – priced the project using mechanical adhesive (screws) and no weather barrier (against the manufacturer’s instructions). Within a few days the the plywood substrate is covered and no one who is knowledgeable on the subject saw the project, or bothered to say anything to the home owner.

Now… even a poorly installed EIFS cladding will last for years, maybe decades. Not only that, but in that time frame it may have even paid for itself in energy savings. Because there is no weather barrier however, and the home owner didn’t know any better, in 15 years a home inspection is done and mould is discovered. It has rotted the plywood and moved into wall studs. The home owner is told that the mould may be harmful to their health, and is compromising the structural integrity of the wood studs, and needs to be replaced immediately. The home owner ends up incurring cost after cost:

  • $4,000 for mould remediation…
  • $5,000 to remove the defective EIFS…
  • $4,000 for a carpenter to replace the wood studs and plywood…
  • …and in a perfect world $16,000 for the EIFS to be properly re-installed.

That’s over $29,000 of out of pocket expenses, and another $30,000 to sue a contractor… if you can find him. Unfortunately, the reputation of EIFS is frequently (and wrongfully) tarnished in these situations, because of the unscrupulous morals of a single contractor and the lack of discretion from a home owner. In the end, it always benefits the home owner to pay the little extra and ensure the job gets done right the first time. That isn’t to say that paying more will ensure your job is done properly though.

When all is said and done, most people end up around the $10-12 per square foot range, when doing a large part of their home. When doing a smaller part (less than 300 square feet), it’s more common to see prices in the $15+ per square foot range.

Sign up to receive a stucco quote the main page to get information on what to look for and ensure that you your home renovation project is done right.

The EIFS Lies Countinue

Posted by Admin on December 8, 2009 None comments

Source: http://www.scottshepard.net/remaxil/modules/agent/agent.asp?p=pagecontent.asp&nav=1&pid=42&acc=89890

It’s ironic this guy’s last name is Shepard, because he’s leading his clients astray. Even today, uninformed real estate agents, building inspectors and many others are posting and re-posting false information about EIFS. I just need to address a few of the issues with this article:

1)

In 1994, moisture damage to the interior of walls was being linked to EIFS. In August 1995, 32 EIFS clad homes in North Carolina were tested and 30 were found to have moisture problems. In January 1996, the National Association of Home Builders issued a “Builders Alert” about EIFS. In May 1996, Raleigh North Carolina, imposed a moratorium on the product through January 1997. In March 1996, the North Carolina Building Code Council adopted stringent guidelines for the application of EIFS mandating that a drainage system be installed in the exterior walls of EIFS homes. By September 1996, twelve class-action lawsuits had been launched in the States. In September 1996, Maryland Casualty Company notified its clients, who were contractors, that work with EIFS systems would no longer be insurable. At about the same time, a major relocation company advised its clients that it would eliminate the guarantee on EIFS homes for employees seeking their services during a transfer.

The Mortgage Division of the Chevy Chase Bank decided about the same time to no longer accept mortgages on houses built with Synthetic Stucco. In January 1997, the Georgia Association of Realtors changed its property disclosure statement to disclose whether the house was built with EIFS.

It’s amazing how things can look bad when you stop half way through History. Could you imagine if we only knew about world war 2 up until 1940? I’d be scared for my life that Hitler was in power. That’s exactly what these uninformed “professionals” have done. Further testing revealed that the source of water intrusion was around window penetrations due to poorly specified and installed details. North Carolina later found that this problem was not exclusive by any means to EIFS, but to just about any cladding. Jump forward a few more years, and barrier EIFS (the type where the moisture problems were possibly with – are no longer being recommended by manufacturers, but have been replaced by a new system – dual-barrier/drainage EIFS.

2)

There are many different systems offered by various manufacturers, but in general, EIFS wall systems consist of a wood frame wall (usually 2×4 or 2×6 lumber), covered with sheathing such as plywood, OSB, or gypsum board. Plastic foam insulation boards are then glued or fastened to the sheathing. A 1/16- to 1/4- inch-thick stucco base coat is troweled on to the insulation. A glass fiber reinforcing mesh is imbedded in the base coat. Finally, a finished coat is sprayed, troweled or rolled on. This finish coat provides the color and texture of the home. Many installations have no building paper or housewrap behind the stucco to act as a backup material.

Again, this WAS the situation with EIFS, but isn’t any longer.

3)

Rainwater appears to be getting into the wall systems through imperfections in the stucco. These include joints around windows and doors and penetrations from railings, wiring, plumbing, vents, etc. Once water gets behind the system it gets trapped, leading to mold, mildew and rot of the sheathing, studs, flooring and other framing members. EIFS houses often look good until sections of the wall are removed revealing concealed damage. The damage can even take place within the first few years of the home’s life. As most of the damage has been found in houses in coastal areas, some have suggested that condensation is a problem; however, since the most severe damage seems to show up around wall penetrations, condensation does not appear to be the culprit. The worst damage is often found below and beside windows.

Modern EIFS allow water to drain, not trapping it any more. Penetrations around window should hardly be considered “imperfections” in the stucco as it’s a detail that the original builder should have properly finished, and not specifically related to EIFS.

4)

There is little that can be done on existing systems short of re-siding or paying fanatical attention to keeping the water out. Caulking and flashing maintenance should be a high priority for people with synthetic stucco houses.

In the very newest installations, contractors are using building paper or housewrap behind the insulation to protect the sheathing. In addition, the newest installations are designed with a drainage system behind the insulation to allow any water, which does get in, to drain out. This is not unlike the drainage system found in a brick veneer home. These improvements should work but only if they are well constructed.

The first point is a good one for any cladding – caulking needs to be replaced as required on any home. This typically needs to be done every 5-10 years for optimal performance, and a sure sign is that it’s cracking or peeling off the frame to which it’s attached.

5)

So far we know that areas of high rain fall, and particularly areas with rain accompanied by wind, result in houses with the most damage. Homes, which have no roof, overhang, a very small overhang or many penetrations through the wall systems (i.e. lots of windows and doors) are also at risk. Unfortunately, a visual inspection cannot tell the whole story and until invasive testing becomes standardized and sufficient data becomes available for our area, concealed damage in synthetic stucco houses will remain a question mark.  If you were planning to purchase or sell a home with EIFS that was installed before 1998, we would recommend a full EIFS inspection be performed and included with your closing documents.

Finally, something I can agree with. Any home a high-rain/wind (i.e. coastal) area is most susceptible to damage, EIFS or not. Small roof overhangs and lots of windows do increase the chances of problems in a cladding. Older EIFS installations do need to be inspected, and an EIFS-specific inspector is what is recommended. That’s not to say all new installations are perfect, EIFS is a very technically installation and there are a lot of contractors out there who are looking to make a quick buck, with no regard to their client or the industry they’re damaging.

Who’s Tim Oglesby? Supposedly “educated professional”: http://activerain.com/homecheck

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.