Deadlines, Roadblocks, & Reality

We missed a major deadline last Friday, which in reality had no chance of ever being met.

In order to meet my prescribed schedule (get dry before Sept 30), I had identified Friday the 8th of March as the day I needed to apply for permits.  I had allowed 4 weeks for the permit process and anticipated starting to dismantle the existing dwelling in mid April.

A visit to the District Hall on Friday identified that this schedule was unrealistic on many fronts and will need to be completely rethought. Up until this point, I have had this naive assumption that everything would just fall into place as I progressed through the planning and build process. I was counting on good karma to be by my side and pave all the paths through the myriad of steps leading up to and through the build.

Well, it seems I have been optimistic on a laughable scale.

Things turned south the first time back in September of 2011 when I found out the District was not adopting similar measures, as surrounding municipalities have,  to promote energy-efficient building envelopes (more on this in a separate post).   I should have clued in then, that this would not be ‘easy’.  This led to a 1-year hiatus from active design while I pondered the way forward and advanced my knowledge in the science of building enclosures.  In September of 2012, I restarted the design with a goal to reduce footprint and harvest as much solar energy as practical for my region and lot.  I have put considerable effort into finalizing this design over the last 6 months ramping up over the last two months to 'full time' in order to complete the 3D model and 2D plans in time for this week’s permit application (something I was generally successful in doing).

But then a string of current setbacks made this timeframe impossible to meet, starting with the structural engineering which I had assumed would be straightforward and quick.  Earlier last week I had to part ways with the initial structural engineer I had chosen for the project.  Within the course of our first real day of activity on the design, it became clear that he was not the right person for the job.  I needed someone familiar with Insulated Concrete Foundations (ICF) and someone who was proficient with Part 9 construction of the building code and could think outside the box, because this is a fairly innovative design that will not have been seen by many people.  It became clear pretty quickly that neither of these needs was going to be filled by my original selection, and we both agreed that this was not the right project for him.  I had learned long ago to go with my gut when working with people, and was relieved at how quickly this situation came to a resolution.  Recently, I had witnessed a friend's build, where a gut feeling was put aside by them in selecting an architect, and that decision plagued the entire build, which further reinforced my conviction.   I vowed that I would not repeat this experience.

This left me with under a week to find an engineer and complete the structural design so that I could still submit for permits 'on time'. This turned into the second major roadblock as I was unable  to find any engineers familiar with ICF that were available on short notice.  This has been compounded by a lawsuit currently in the works (to the tune of $1M) involving an ICF project in the Lower Mainland where the dwelling had to be torn down after construction due to a faulty ICF foundation installation.  News of this lawsuit is spreading across the engineering community and I spoke with two engineers this last week who no longer design in ICF construction. In speaking with the engineer who is acting as the expert witness for the plaintiff in this case, it appeared that there were concerns with one of the major brands of foam ICF, and how the structural rebar is held in place (or not), and also a concern on the ability of the concrete to fully encase the rebar in this ICF design.  I am not proposing to use this foam ICF, or any foam ICF for that matter, and will try to pry an assessment of the system I would like to use from this individual over lunch sometime soon.

With any hope of engineering completion at least a month or more away, I went to the District Hall yesterday to enquire about the permit application process.  An engineer had mentioned I could apply for the permits without the calculations being completed and just submit the calc’s when needed during the plans review process.  This was not a strategy recommended by the District.  They advised that checking would not proceed without all required documents.  So I really need a complete package before submitting my application.  Realistically this would set the start back a month or more.

While at the District, I was also informed that the approval process was currently taking 6 weeks or more and that because I would need to apply for a variance, I could probably expect double that time.  So all together I was looking at around a 3-4 month delay in the commencement of the build. This would prevent me from getting the roof on and the place generally water-proof until Dec/Jan which is a build condition I am unwilling to accept.  It has been my intention from day one that I would not be doing exterior construction during the wettest and coldest months of the year in order to protect sensitive building materials like the TGI's from becoming saturated and because it just is not any fun building in the cold or torrential rains (I remember my first winter job site experience where we had to build a fire each morning to thaw out the pneumatic lines).

The final stumbling block presented by the District Friday, was an initial refusal to allow a holiday trailer to be parked on site, which I propose to live in during the build.  This is key to our budget, as rent in my neighbourhood is around $1600 for basement suites and $4000+ for upper floors of a house.  With the anticipated build time of 18 months, this would result in a $30K - $75K reduction in our available budget (10% - 20%), and a serious challenge to our cash flow. The District is concerned about site safety and the safety of their services which I totally understand, but I am confident that solutions exist for all of the concerns if we just think a little bit out of the box.

This all lead to a decision on Friday to delay the project start date by a year.  I will still work on completing the design, getting material pricing, solving the living on site issue, putting some much needed attention into the onside Building Lab project, and just generally getting better prepared for the build.  But I will hold off applying for permits until probably September.  This would give the approval process six months before we would anticipate breaking ground.

I am significantly relieved by this decision, as although I was ready for the building permit, I had not finished the electrical and plumbing design and would have had to work those out during the evenings as I was building.  This way I can thoroughly prepare all aspects of the build and be in much better shape next March.  This will also allow me to concentrate on some landscaping in the back yard this year, which will make neighbours very happy.  This also gives more time to get the project’s website up and running.  

On some levels I feel like I have failed, and I have.  But in a larger regard, I have succeeded to make the right decision to ensure the desired successful outcome, and for that I am proud.

I will continue to document my journey over the next year as there will be many decisions I can now research before making.  Does ICF make sense?  Why do I want to buy floor trusses from Quebec? Rain Water and Grey Water Heat Recovery, do they make sense?  How much of an existing structure can be diverted from a landfill?

I hope you will continue to visit, and I look forward to any comments or questions you might have.

Product Testing Continues at SENWiEco

SENWiEco continues testing products that we hope to incorporate into our upcoming build.

The R-Guard products from Prosoco are standing up well to our accelerated temperature torture testing.

After 7 days of extreme testing, the Durisol ICF block shows no sign of capillary action horizontally through the product.

We have now started testing the waterproof capacity of Fab-Form's FastFoot fabric footing forms.

SENWiEco considers the Durisol CBWF ICF Block for below grade foundations

Anyone who has read my previous blog entries knows by now that I like to verify and do things for myself.  SO it should come as no surprise that I will perform some testing on another ‘new’ product I am considering for my upcoming build.

As mentioned repeatedly on my blog, my focus on this build is a bullet proof and energy efficient building enclosure to lower my impact to this planet.  I am targeting R10/20/40/60 (Slab/Foundation/Walls/Roof) and these are effective values not nominal (so values after taking into consideration all thermal bridging). 

With these targets identified, it makes sense to optimize what ever insulation is installed by placing in locations less effected by thermal bridging.  This usually means putting most/all of the insulation on the interior of the structure or exterior of the wall or roof assemblies.  Now which side you put the insulation on is very important for preventing condensation.  In a Cold-heating-dominated-climate like Vancouver, you want to keep the sheathing above the dew-point potential so that if any interior air leaks into the wall assembly, it will not condense on the back side of the sheathing which can often cause rot and mould. 

Continuous exterior insulation is a great way to prevent thermal bridging (your insulation is firing on all cylinders) and keeps your sheathing, or in this case your foundation walls, warm and dry.  For this reason, an ICF form system makes a lot of sense.  In typical ICF formed walls, there is an interior panel of insulation attached to an exterior panel of insulation with plastic or metal ties.  The concrete is then placed to fill in the gap down the middle. 

From an insulation point of view, the continuous nature of the ICF panels is great and represents a thermal bridge free design.  Your nominal insulation is the same as your effective insulation R values.  However, you do end up with a thickness of insulation on the interior face of the foundation.  This prevents the concrete from acting as a thermal mass that would otherwise allow it to help moderate interior temperatures.  Insulation inboard of the concrete core can also represent a dew-point potential if the concrete pulls away from the foam as it cures and air leakage results.  Finally as the product is made from oil, it can represent strong off gassing potential and a real fire spread and toxic fumes risk if your drywall is not continuous or is damaged and a fire occurs.

But for me, the biggest demerit, against the foam based ICF’s, is that they are made from foam and therefore oil.  If your goal of creating a low energy house is to reduce your impact on the planet, it hardly makes sense to use a product that is the most responsible for human’s impact on the planet today.  We will be no further ahead if we create a demand for foam ICF on a mass scale, as this will just continue the dependence on a product we really need to start considering leaving in the ground.

Now many of you will say the benefits of foam ICF outweigh the use of an oil derived product.  You are at least locking away a lot of the carbon that would be created if the oil was otherwise used for combustion.  At least in a product like this, it will stay buried for probably 50-100 years (and there may even be a potential of recycling the product at the end).  And any increase in insulation decreases the amount of electricity and gas used in homes to provide heat and air conditioning. To an extent, I agree with this rational.  I do not believe you should abandon products just because they are made of oil.  In many categories, the alternative ‘green’ products are not suitable for use and have durability issues.  The regular replacement of an unsuitable component can represent just as large an embodied energy, as using a more suitable oil derived product.  However when you do have a suitable non-oil based alternative, you should do everything possible to incorporate it into your design. It was with this frame of mind, that I started looking at the Durisol ICF block for my upcoming build.

The benefits of a cement-bonded-wood-fibre (CBWF) block are:

• Made from recycled-wood and cement powder,
• Places all of its insulation outboard of the slab,
• Can be left as a final surface within the basement,
• Can be attached to anywhere in the field of wall (do not need to hunt for hidden plastic tabs to fasten drywall or framing to),
• Incorporates a drainage plane within the product,
• Is mold and rot resistant,
• Is bug and rodent proof, and
• Best of all – does not burn easily or give off noxious fumes if it does. 

Now for its negatives:

• Highly air permeable (a benefit of regular ICF is that the concrete core is an air barrier).  The material of these blocks is highly porous and the block has webs that connect the outer and inner panels together THROUGH the concrete core.
• These webs are not just an air path; they are also possible water and likely a vapour path.
• There is at least a passing concern that the block could rot in a below grade application.

In researching this product, I was unable to find any comments on-line that the product had ever broken down below grade from decay.  The manufacturer provided an Ontario MOT testimonial that stated they had never had to repair the product due to decay (the product is used extensively above ground, and partially submerged, as a road side noise abatement fences) after 30 years of use. 

The product has been manufactured since 1953, so certainly has been on the market a long time.  If there were significant failures, it would be readily visible on the web. 

So what’s the catch? 

Well the product has not had a huge uptake for below grade installations to date.  The manufactures claims they have a dozen or so projects a year on average in Ontario and I have found 2-3 blogs on the net describing the use of the product.

What’s the risk?

Well, unlike traditional ICF, the interconnecting webs of each block penetrate through the concrete core.  This provides a path for air, vapour, and possibly moisture travel. 

The air barrier is fairly easy to address with a fully adhered membrane outboard of the block (this still leaves some interesting details at the footing level and will probably require some thinking out of the box to seal on the interior face near the basement floor slab - more on this in the future). An airtight drywall approach (ADA) could also be implemented.

The vapour barrier again will be generally dealt with by the fully adhered exterior membrane. Besides, even regular formed concrete foundations have a considerable moisture movement through them from out to in, which is why you should never have a vapour barrier (just a retarder) beneath the drywall in the below grade basement (NO POLY! EVER!!!).

Now for the real issue: What is the danger of liquid water transport through the webs to the interior face of the block, either under hydraulic pressure or capillary action? 

Durisol partnered with the University of Toronto to study the drainage properties of the CBWF ICF block back in the mid to late 90’s.  This UOFT report confirmed the manufacturer’s claims that the product did not support horizontal capillary movement and that liquid moisture drained readily through the material.  In fact the free draining rate of the product was a whopping .5 gpm through a piece of material that was 3.5” Thick, 8” wide and 11.3’ (yes ft) tall.  In another test, where a sample was fully saturated and then allowed to air dry, the retained moisture after 60 minutes was only 38% and the sample had lost a majority of its moisture after just ten minutes.

So far, this all looks great!

Figure 1: Durisol 12” Thermal Block in the R21 configuration (5.5” Concrete Core)

Figure 2: (LEFT) Semi-rigid mineral wool insulation insert on the outboard side of the block. (RIGHT) Product is created with a mixture of recycled-clean-mineralized-wood-fibre and cement powder.

 

 

 

But unfortunately, I rarely accept others reported results at face value.  I wanted to put the product through a more rigorous testing protocol (in my opinion).  So enter the DBTTC or Durisol Block Torture Testing Chamber!

Figure 3: (Left) 28”l x 19”w x 15”t tub with a selection of Cactus Club takeout containers as standoffs in the bottom.  These support the block without being susceptible to rising damp.  They also isolate the outer and inner webs so that water flowing down the outer web does not flow along the support to the inner web. (Middle) A small water pump is rated for 70 GPH @ 0” head so probably around 40-50 GPH in my configuration. (Right) The containers are 2.5” tall and the water level was set at the halfway point so there is approximately ¾” gap from the top of the water to the bottom of the block (should allow for enough air movement around the bottom of the block so that the humidity does not build up too high and skew the results.

Figure 4: The inboard side of the block surface registered at 11.1% MC.  The block has been sitting in my living room for about a week (which by the way, translates to an indoor air relative humidly of 55% which is what I have the bathroom fan humidistat set to).

Figure 5: I also took the MC of the webs from within the inside journals that the concrete would be placed in.  This will be an easier location to monitor.  I had a reading of 10.4 and 9.3% MC (difference was probably due to a variation in density of the product at the tested location due to the random makeup of the wood fibre).

Figure 6: The Test

Over the next week or so, I will leave the pump on 24/7.  Water flows out of the plastic tube that has been drilled with holes at a regular interval.  The water is draining through the outer panel as fast as it is added at the top where it drips back into the tub and repeats the cycle.

Over time, I will measure the moisture content of the inboard panel exterior face (and the side faces of the internal webs).  The go/no go test will be to see if a piece of paper stapled to the inboard face of the block shows any signs of moisture over time.

I will of course post the results once they have been tabulated.  Here is a video showing the start of the test and another video showing 60 hours into the test.  At this point, there has been no horizontal travel of liquid towards the interior panel, which confirms the testing performed by the University of Toronto.