www.TrappeurHomes.com is a blog with updates about the latest log home products, building efficiency, and any other new products and procedures for renovation or building a home.
Aaron Cameron, my business partner with TrappeurHomes.com, Chris Wiegert , home builder in Columbia Valley, and I did a business trip to Powder King (near Mackenzie) and rented a Cessna 172 from www.BabinAir.com for the 680 km trip.
There is nothing better then flying in the pristine Rockies Mountain trench in the winter. There are no words to describe the beauty, vast, wild and untouched landscape and even the pictures are not doing justice either.
Skiing at Powder King was fantastic. Amazing hosts, super nice people and excellent snow.
Thanks again to everyone making us feel so special.
We had to change our flight plan on the flight back due unsettled weather and it turned out to be a very exciting and scenic flight back via Prince George, Williams Lake, Kamloops, Revelstoke and the Rogers Pass.
Finding mold within a wall or roof assembly when renovating a newer building is common today.
First we thought this happens only in older buildings if the vapor barrier was not installed correctly.
The question is, why do we often find mold in newer buildings?
We did some research and started to look at older conventional building techniques which had no mold problems and did not use any vapor barrier.
In order to get a better understanding of what is going on within a wall, we analyzed different types of wall systems using the "Glaser Diagram" or "Profile Method".
In short, the "Glaser Diagram" or "Profile Method" is a diagram which displays a temperature gradient and a vapor pressure gradient through a wall section.
Frank Rowley produced a seminal paper in 1938, which drew both a temperature gradient and a vapor pressure gradient through a wall section. Helmut Glaser did a similar test and created the Glaser diagram in the mid 1950's.
Like many aspects of building physics, vapor diffusion first became the subject of academic study because there was a problem that needed both an explanation and a solution.
Here is what we read in a blog (The Little Known History of the Vapour Barrier) from Mark Brinkley.
The story is told in fascinating detail in William Rose’s book Moisture in Buildings. The problem was first noticed in the 1930s by American house painters engaged on painting the external timber claddings, or sidings as they call them, which were and still are so prevalent there. They reckoned that they were getting more problems and more call backs on jobs where the walls had been insulated. Ergo, there was something about adding insulation to the walls that was causing the paint on the wall sidings to peel, crack or whatever.
In a nutshell, the blog states, adding insulation increased the moisture content and drying time of the wall and created the exterior paint problems.
Frank Rowley's solution to eliminate moisture within the building assembly was to apply a vapor barrier installed inside the wall which was adopted in the building code worldwide.
Based on Rowley's and Glaser's research and using the vapor barrier, there should be no moisture and no mold build up within the wall or roof assembly, but there is.
So what is going on?
Based on the "Door Blower Test" it shows that no building is really 100% air tight, meaning moisture is able to get into the wall system.
Further, Rowley took great pains to eliminate the effects of both radiant and convective heat transfer, because the theory rested on comparing the rates of heat conduction with vapor pressure.
The fact that his initial experiments were carried out in conditions very different to the typical house wall was ignored.
In testing for vapor diffusion, he deliberately eliminated the effects of heat transfer by convection, radiation and air movements.
He was also only measuring the airborne water vapor in the air: the far bigger reservoir of bound water in the materials was overlooked, possibly because it wasn't generally understood at the time.
William B. Rose, author of the book "Water in Buildings" and Senior Research Architect in the Indoor Climate Research & Training (ICRT) program made the following statement:
The principal criticism on Rowley’s research (around 1938) is this: The “Profile Method” cannot detect types of moisture problems other than those related to diffusion. An informal survey among building scientist colleagues seems to indicate that diffusion-related moisture problems account for less than 1% of moisture problems found in buildings. We have been seriously side tracked by the emphasis the profile method has received in the last 50 years.”
Bill Rose shows with a very simple sealed jam jar experiment that there are way more complex variables occuring within a wall assembly.
If you heat the air within a sealed jam far, the humidity level decreases, due to the fact that warm air can hold more moisture than cold air. The moisture content is still the same, but the humidity level (in %) dropped.
The question is, what happens if you have a cube of wood in the sealed jam jar? How does this affect the humidity level and humidity content?
The experiment shows that heat will force out the humidity from the wood and the humidity level and content within the sealed jam jar increases.
As a practical example, in today's outdoor survival training one uses this simple method in order to create drinking water. By collecting leaves and branches and sealing them in a plastic bag and exposing it to the sun, the heat will force the moisture out of the leaves and wood and the result is drinking water.
Based on this experiment and knowing that most of our lumber (even kiln dried) still stores a large amount of water within it, and if the industry continues to seal the outside of the wall, the humidity within the wall and roof assembly has no chance to dry out. With this condensation, mold will start to grow.
Our conclusion Today's wall and roof assemblies are built way to airtight.
The "Glaser Diagram" shows very clearly that in today's wall assemblies, the drying rate of an average wall is over 100 days versus about 40 days in older wall assemblies.
The lesson we (www.TrappeurHomes.com) learned, based on our research, is:
Work with what you have
Moisture will always be in a wall
Don't try to build a sealed building envelope
to keep moisture out.....this will also keep moisture within.
In the last couple of months we have been working closely with our friend Tomaz Stich, stich consulting & design (Passive Home designer) He has helped us in working with the Glaser diagrams and has made us aware of a lot of options and materials. With Tomaz, we have learned about the following products:
The INTELLO Primer
The INTELLO membrane, manufactured by Pro Clima of Schwetzingen Germany, is the state-of-the-art for interior vapor control and air-tightness for cold and mixed climates. It is an intelligent membrane that changes permeability in a range from 0.17 perms in winter to over 13 perms in summer depending on the relative humidity around it. This intelligent range of permeability can give assemblies maximum protection against moisture damage.
Drying Capacity > Moisture Stress = Freedom from Damage
Premium Wood Fibre Board - The Smart Choice for Insulation Board
Best would be to replace OSB or plywood with the Wood Fibre Board. The Wood Fiblre Board is not a structural sheeting and you would need to use wire strapping to get the lateral stability of the wall.
Here are the benefits of the Wood Fibre Board:
Open to vapor diffusion (will not trap moisture)
Works as a windproof layer (replacing the building wrap). To create a continuous seal, the boards come with T&G edges.
Offers a great thermal insulation value and excellent heat storage capacity helping to protect the building from overheating during hot summer days.
Water resistant yet can absorb 10% of its own weight in water vapor.
100% recycled and recyclable materials (wood fibre, starch and wax).
We also have a blog with more information about the Wood Fibre Board at www.TrappeurHomes.com
If you have any feedback or interest in purchasing the Intello Membrane or the Wood Fibre Board (T&G) please contact us at build@TrappeurHomes.com or at the Invermere Home Hardware Store.
Preventing mold problems and Creating a highly efficient, “Green” and cost effective building envelope for Architects, designers, contractors, inspectors and homeowners
Mold is becoming a well known problem many renovation carpenters see everyday. Even newer buildings are susceptible to this increasingly major issue. Industry standard is to install a vapor barrier on the inside to block moisture from penetrating the assembly and apply OSB or plywood (for strength) and house wrap (to block the elements) on the outside. We trust these methods and products to work but judging by the magnitude and widespread nature of the mold problems, they are obviously not working well enough.
TrappeurHomes.com has found several simple innovative solutions and new products that greatly improve on the ‘industry standard’ for controlling moisture in your building assemblies.
We are excited to share this knowledge with everyone who is interested in healthy houses.
To learn more about how and why mold forms within building assemblies join Max & Aaron
at
Invermere’s College of the Rockies
March 12 @ 7:00PM
for a FREE workshop
We are also planning to run FREE Workshops in March atGolden, Fernie, Kimberly and Creston. (We will update the dates as soon we got confirmation)
I have been at a workshop with Prof. Tang Lee (professor at the the University of Calgary, a AAA architect and solar technology specialist) at the "Green Building" conference in Kimberly and learned a lot about how easy and simple it is to collect and use/store solar energy.
The most important experience and lesson Mr. Lee shared with us was this: Don't strive for 100% results, it requires too much money and effort. Be happy with 70-80%, it achieves what you want for a fraction of the cost and work. This is the "sweet spot" if you will.
Example: Mr Lee created the most optimized house with solar panels in 1975 which took them an enormous effort to calculate and build. After the fact, he realized that he could have easily achieved 70-80% of the energy with a fraction of the effort and cost. Meaning, to get 100% of the possible solar energy in relation to the cost it made no sense. The cost and effort in relation to get only 70-80% of the possible solar energy makes sense and will pay for it's self.
With this lesson in mind, Prof Tang Lee states that a metal roof is the simplest, easiest and most practical way to collect and use/store solar energy.
The only modification when installing a metal roof is to add vertical strapping to create an additional airspace between the sheeting and the metal roof so the heated air can travel to the ridge. Below and along the ridge there will be a framed and insulated box to trap the hot air. Once the hot air reaches a certain temperature, a thermostat will turn on a small blower to pump the hot air into an insulated cabinet housing an un-insulated hot water tank. This preheats the water (about 30°C to 50°C) before it gets into the hot water boiler. This alone will save about 80% of the hot water heating costs.
In the winter time, the hot air can additionally be used to heat the concrete slab by simply pumping the hot air in a grid of 2 feet centered non porous weeping tiles to heat up the ground and concrete.
This is a very simple, easy to install and cheap investment which will save heating costs on an ongoing basis.
Thanks again to Prof. Tang Lee for sharing and helping to create a smaller ecological footprint and to save money.
We at www.TrappeurHomes.com are supporting this idea and will try to implement the simple technology into our houses.
Bondu Log Homes have been on the market since 1973 and have proven their high efficiency wall system over the years.
We at www.TrappeurHomes.com took it a step further and added a 1.5 inch thick Wood Fibre Board Panel between the log wall and the interior 2"x4" insulated wall.
Here are the benefits of the Wood Fibre Board:
Avoids thermal bridging between the outer log wall and the inner framed wall by acting as a complete thermal break between the two
Open to vapour diffusion (will not trap moisture)
Works as a windproof layer (replacing the building wrap). To create a continuous seal, the boards come with T&G edges.
Offers a great thermal insulation value and excellent heat storage capacity helping to protect the building from overheating during hot summer days.
Water resistant yet can absorb 10% of its own weight in water vapour.
100% recycled and recyclable materials (wood fibre, starch and wax).
Wood Fibre Board is not for the exterior wall but is also ideal for :
Interior walls - sound proofing
Roof sheeting - thermal break and extra insulation
Floor underlay - extra insulation and sound proofing
Renovations - added insulation, windstop and sound proofing.
Overall, this Premium Wood Fibre Board is:
Economical
A higher efficiency than standard plywood walls means lower heat loss. Ultimately, this means more money in your wallet year after year.
Efficient
Wood fiberboard panels have a high heat storage capability and excellent thermal insulation properties.
Sustainable
All our products are made with 100% recycled and recyclable products that are natural and non-toxic.
for more information and to order for your house visit
Happy New Year to everybody.
We, at TrappeurHomes.com, are looking forward to a very exciting year.
Overall, since we started, we have had tremendous feedback, and it is fantastic to see how people and contractors are interested in simple, cost effective, "Green", healthy and high efficient housing.
We have been in contact with several Trappeur Log Home owners here in our area and we have had nothing but very positive feedback in how their homes (some are 20 years of age) perform and function, and how they visually stand out amongst other homes. The feedback from Realtor's too, is nothing but positive, with statements that our homes are selling faster then others due the timeless design, craftsmanship and quality.
We will be posting a testimonial page on our website soon.
Our philosophy is that "good look", "Green", top craftsmanship and high efficiency does not have to come at an astronomical price.
Kootenay Business Magazine has featured Trappeur Homes in the January 2014 issue. We are very happy with the article, and it is well worth the read. Click here to see the article.
We have also come a long way with our "open/breathable" wall system and our new vapor barrier. The Regional District of the East Kootenays welcomed our approach and we currently have an engineer working on the legality to have it approved for BC and Alberta.
We are looking forward to the next few months as it will be very exciting to get the first couple of buildings off the ground as soon spring arrives.
The biggest trend in construction right now is designing and building highly efficient homes or even a "Passive House" to reduce our ecological footprint. Most people understand a highly efficient home to simply have the highest R-value materials for insulation. This is not really true.
As an example, a "Passive House" (considered the gold standard of high efficiency) does not require specific R-values. Instead it looks more at how much energy is used per square meter in a year for operating, heating and cooling the house. In order to achieve this standard a lot of other aspects need to be considered, such as passive solar design and landscape, window technology, airtightness, ventilation, space heating, lighting fixtures, electrical appliances and insulation.
In other words, achieving this "Gold Standard" is not as simple as only looking at R-values.
The Canadian building code mainly considers R-values for insulation, which doesn't really tell you the whole truth about how efficient a building is. Research has proven that a well built log home which only has an R-value of between 6 - 9 will have the same heating and cooling costs as a conventional 2"x6" stick framed and insulated building with an R-value of 22. In fact, the Canadian building code will accept the R-value of a log house build with a 150 millimeter wide log or bigger.
How can a simple log with such a low R-value be as efficient as a 2"x6" insulated wall?
The answer is "Thermal mass"
In short, "Thermal mass" is the concept of "inertia" against temperature fluctuations.
For example, when outside temperatures are fluctuating throughout the day, a large thermal mass within the insulated portion of a house can serve to "flatten out" the daily temperature fluctuations, since the thermal mass will absorb thermal energy when the surroundings are higher in temperature than the mass, and give thermal energy back when the surroundings are cooler, without reaching thermal equilibrium. (this statement is from Wikipedia)
If we look at the Trappeur Homes wall design with the Bondu dovetail logs, we do have a very good thermal mass value due to the logs alone. Further, we add 1.5 inches of wood fiber board inside the Bondu Logs which offers an additional high thermal mass value. This 100% recycled wood-fibre board also provides additional insulation, acts as a wind breaker and becomes a complete thermal break (to avoid thermal bridging) between the log wall and inside framed wall.
Our standard wall system uses a 2"X4" inside framed wall and is rated at R-26 which is a bit more then a conventional 2"X6" stick framed and insulated wall at R-22. With a 2"X6" inside framed wall our Trappeur Homes wall assembly is rated at R-34 (for those who want more).
Considering R-Values alone it appears there is not a big difference between our R-26 wall and a stick framed R-22 wall, but have a look at the diagram to the left showing the outside and inside surface temperature changes during the day. The inside surface temperature stays very stable due to a very high heat protection value of 22.3 from the thermal mass giving us a temperature phase shift of 15.2 hours.
A similar chart on the right shows a conventional 2"X6" stick framed and insulated wall (R-22). The heat protection value is only 3.0 which gives a temperature phase shift of only 5.5 hours leading to fast and significant inside surface temperature changes. You can see the inside surface temperature is not very stable compared to the above diagram showing the Trappeur Homes wall system (Blue Line).
This explains how the thermal mass in a Trappeur Home helps it stay way cooler in the summer and makes it much more efficient than a conventional stick framed building.
Research reference:
According to our interpretations of information from the Canadian Construction Materials Center and the Model National Energy Code (1997), a 150mm milled log wall need not comply with effective thermal resistance requirements, as trade off calculations for this type of log structure are permitted.
For purposes of trade off calculations, a 150mm milled log wall shall be taken as RSI = 1.3. Round Scribed log walls shall be taken as RSI = 2. SPF, (spruce, pine, fir) as the wood species.
For more complete information, please consult the:
Technical guide for Milled-log Buildings, report 13142 , Milled Log Houses report 13140 (5.2.1) and Model National Energy Code of Canada for Houses (1997) (3.3.1.2)
Canadian Construction Materials Center
Ottawa (Ontario)
Canada K1A 0R6
Other studies conducted in some northern states of the USA showed that R-values may be increased substantially to account for the thermal mass storage and thermal lag of solid wood walls.
In 1991, the NAHB (National Association of Home Builders) Research Center conducted a study for the LHC (Log Homes Council). This study showed that“ the thermal mass of log walls significantly reduces energy use for heating in cold climates. The study compared the actual energy use by eight log homes and eight well insulated foam houses during one winter. The houses were evenly divided between upstate New-York and Montana. The study also compared the home’s actual energy consumption. The results led to the conclusion that log homes are as energy efficient as frame houses, even though the average R-value of the log walls was 44 percent lower than the R-value of the frame walls.
More complete information is available in the:
Research Report on Energy Efficiency of Log Buildings published by the
Log Homes Council National Association of Home Builders
15th & M. Streets, N.W.
Washington, D.C. 20005
USA
