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Expert: Ted Barnhill (Principal, Design45 LLC) - 2/16/2011


Question

Main Floor Drawing 1
Hello Ted.
I plan to make a number of changes to open up the small 840 sq ft stick built house which we have just purchased as our retirement home. I will begin by removing a load bearing wall between the living room and kitchen. The current living room will then become a large dining room. Then I will open up and develop the attic of our 1 ½ story house so as to create a nice large living room. This will necessitate building stairs to the attic as the house currently does not have inside access to the 2nd half story; I currently have to enter the attic by climbing up on the carport and crawling in thru a window.
I have attached two drawings, and drawing 1 shows the 10 ft 8” part of the main floor wall that I want to remove. This wall sits directly on the main beam that runs across the basement as shown in drawing 2. My questions are:
1)   Is the wood beam in the basement strong enough to support the renovations I plan to make with only the two wood support pillars that are currently in place or should I add additional teleposts? This beam is 7 1/4” wide by 7” high and is made of solid fir.
2)   How can I determine the dimensions of the beam that I will I need to insert to replace the 10’ 8” length of wall? I would like the beam to show when the work is completed.
The floor joists supporting the main floor are 2 x 10’s, while the floor joists in the attic are 2 x 6’s, all on 16” centers. The roof has a 6/12 pitch and is made of 2 x 4’s also on 16” centers. We live in Winnipeg, which gets lots of snow each winter, so snow loads will need to be factored in as well. I plan to create a cold roof by attaching additional 2 x 4’s above the current roof after removing the shingles, which will then be replaced with a metal roof. I plan to blow in 3 ½” of foam between the original 2 x 4’s so that it forms a vapour/air barrier in addition to providing about R25 insulation. (I would like more but can’t think of a way to accomplish this.)
  I am newly retired so have lots of time but not too many funds so I plan to do most of the work myself. Any advice you can offer would be most appreciated.
  Bill in Winnipeg

Answer
Bill,

1. Your basement beam is probably not adequate to support the two new point loads coming down from the columns (jack & trimmer studs) at your new living room beam.  If the basement plan allows, your best solution is to insert new columns with footings below these two points.  Your lumberyard should be able to confirm the existing beam or recommend solutions.

2. Your local lumberyard can size the beam for your living room opening.  This is a simple matter of checking the code spans charts (for dimensional lumber) or manufacturer charts (for engineered lumber).

3. Your cold roof solution sounds good, though expensive.  You might also consider adding rigid foam panels on top of your existing roof, with 2x4 sleepers above that.  This type of insulation costs less per inch than spray foam and can be easily installed yourself.

By the way, you may want to have a firm budget set before you begin.  Projects like a new roof, new stairs, and spray foam insulation are not usually thought of as "low budget".  Best of luck with your projects.

Ted Barnhill
Design 45 LLC

P.S.  I was at the Winnipeg Folk Festival last summer - great city!
    Questioner's Rating
    Rating(1-10)Knowledgeability = 10Clarity of Response = 10Politeness = 10
    CommentThank you Ted! You have not only given me some invaluable information but suggested a new line of thought on how to deal with the roof. Warm Regards, Bill


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Ted Barnhill (Principal, Design45 LLC)

Expertise

I can answer questions about architectural design, how to work with a designer, and best construction practices for most trades. I specialize in cold-climate design (I'm in Minnesota), older home renovation, and energy-efficient/sustainable design.

Experience

As a Principal of Design45, I design and detail new homes and remodels. I am formally trained in architecture, but have also been a contractor and have experience with many trades. I strive to provide beautiful, durable, and efficient homes for clients and communities of all types and budgets.

Education/Credentials
Undergraduate work at Princeton University (Mathematics), Master's work at the University of Minnesota (Architecture)

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