The job site was very busy today.  We were framing the interior walls in the lower level, measuring the openings for the windows and sliding doors, and signing a Canadian passport application.

Providing a Capillary Break Under the Pressure Treated Bottom Plates

Moisture inside a house is bad because it creates an environment where mold can flourish.  In houses that are very ‘leaky’, the moisture problem is somewhat reduced.  On the other hand, it is exacerbated in a ‘tight’ house.  There is an excellent presentation on GreenBuildingAdvisor.com entitled, ‘Got Mold? Energy Efficiency and Moisture Management‘ that was presented by Mike Guertin and Peter Yost on December 18, 2009.  It is 63 minutes long and well worth watching.

Under our Durability Planning, our integrated project team completed a Durability Risk Evaluation Form that identified all moderate- and high-risk durability issues for the building enclosure.  Then, we developed specific measures to address those issues.  In addition, we identifed and incorprated indoor moisture control measures with our plans.

Given we have an immense amount of concrete in our house, we will have a huge potential pool of moisture in that concrete.  Water can move through concrete into wood, hence building codes require pressure-treated wood wherever wood is in direct contact with concrete.

Water, however, can move through capilliary action through wood and other materails.  Thus, having a pressure treated bottom plate that is resting on concrete will prevent the moisture in the concrete from rotting the bottom plate.  The pressure treated bottom plate may allow the moisture to migrate through it to the stud walls, which may cause mold and rot.

Having a capilliary break between the bottom plate and the concrete prevents water from gaining access to the bottom plate.  We are using a product called ‘Low-E Reflective Insulation‘, which is a reflective insulation and is made of two layers of aluminum foil with a closed cell foam in between (sometimes known as ‘foil-bubble-foil’).   Bryan met Charlie Snow at West Coast Green in San Francisco on October 12, 2009, when they first discussed this project and how Low-E Reflective Insulation would provide significant benefits to increasing the energy performance of the house.

We are using Low-E Reflective Insulation in every instance where wood touches concrete.  An additional benefit in our exterior walls will be to use the Low-E Reflective Insulation between the mud sill and the foundation.  Low-E Reflective Insulation will provide a capilliary break for moisture and provide a tight seal so air cannot go through the wood and the concrete.  This will make our house tighter and more energy efficient.  Although we will have separate termite shields in place, the Low-E Reflective Insulation will provide another defensive barrier for termites.

The Low-E Reflective Reflective Insulation comes in rolls that are 48 inches wide and 125 feet long.  Our framing team cut the Low-E Reflective Insulation into strips 5-1/2 and 3-1/2 inches wide so it could go under 2×6 and 2×4 plates.

Establishing the Window and Sliding Door Opening Dimensions

As we’re framing the lower level we are zeroing in on establishing the exact dimensions for our windows and sliding glass doors.  Annie Rouse (Murray Window and Door) and Dave Edwards (Earth Bound Homes) walked through the house and reviewed the dimensions for each window and sliding glass door.

This task required an immense amount of attention to detail.  Making an error with an aluminum frame and double pane glass will be expensive and look bad.  Also, we pulled in Francisco, who is doing the actual framing on site, on several occasions so we’re all on the same page with how the windows and sliding doors will fit.

Signing a Canadian Passport Application (Guarantor)

Our friend, Mats Menhardt, is a Canadian citizen and requires a new passport (Canadian passports are only valid for five years).  His mother, Trixi, brought his completed passport application to the job site for Bryan to review and sign.

That was easy.

Roll of Low-E Reflective Insulation (48 inches wide by 125 feet long).

Close up of the packaging.

Trimming the Low-E Insulation so it will go under the 2x6 plate. Trimming the insulation was easy and fast.

The Low-E Insulation is under the 2x6 pressure treated plate and it will provide a capilliary break and prevent moisture from moving from the concrete to the wood.

Without the capilliary break, water could move through the pressure treated bottom plate and cause mold and rot in the 2x6 studs.

Dave Edwards (left) with Annie Rouse (back) and Francisco (measuring). Trixi (right) is getting the passport application out for Bryan to sign.

Trixi, holding Mats' completed and signed Canadian passport application.

We have been working with Carole Murray and Annie Rouse of Murray Windows & Door, Inc.  Carole and Annie came to the job site today to review where we are and do some field measurements.  Also, today is the final preparations before we pour concrete in the lower level tomorrow morning.

Carole Murray and Annie Rouse Visit Our Job Site

After meeting with Carole and Annie in their offices in Campbell, Bryan suggested they come to the job site and review the openings for the sliding doors and windows to see the issues first hand.  Although we have computer renderings of the house from various angles, there is no substitute for seeing the scale and connections in person.

Carole has suggested that we change the bifold patio door system that is at the back of our house to a large sliding glass pocket door.  This pocket door will go behind our feature concrete wall in the dining room.  We need to confirm the details on how this will work.  In addition, we will have to submit revised plans to the City of Monte Sereno as this will increase the size of the house by approximately 12 square feet.

Carole Murray (right) and Annie Rouse (left) reviewing the job site.

Annie taking notes.

Final Preparations Before Pouring Concrete Tomorrow

it seems there are always last minute things to do before pouring concrete.  Or, it seems like Bryan leaves things to the last minute.

The two remaining items were for Bryan to (1) insulate the PEX where the supply and return lines come together near the manifold; and (2) take photos of the PEX that will be embedded in concrete. 

Insulating the PEX increases the performance of the system by allowing the supply line (hot) to be insulated from the return line (cold) so the hot water in the supply line is not cooled by the cooler water in the return line.  This important task was easy to do and only took a few minutes.

Taking photos was simply a matter of going around the perimeter with the measuring tape and camera. 

With these two items completed … let’s pour concrete!

Lights on, looking left ...

Looking center ...

And, looking right.

PEX in place by the Snack Area (exit sliding door on the left).

Insulated PEX in concrete in Nik's Room/Lower Powder Room.

PEX coming into manifold in the West Air Handler room. Note the insulated PEX.

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