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33 Answers
2" foam board under exterior siding — what regulations?

I have 2" Dow foam board that I want to apply to the outside siding of my building which is now covered in 0SB. The building inspector wants to know how this complies with Mass building code and what the requirements for the procedure are. Help!

To Typar or not, vapor barrier, nails or screws (and which kind), strapping or furring strip requirements, window and door treatment, etc. I have to spell it out for him and get the OK before I proceed.

Thanks.

In Building Code Questions | Asked By nancy marcus | Jun 30 10
11 Answers
The interior walls within the top floor of my brick 1880s Brooklyn brownstone are peeling.

The walls show signs of water damage in two different rooms. Both rooms have a non-working gas (old manufactured or coal gas) fireplaces where the damage is the most severe. It doesn't appear that the water damage is caused by a roof leak. The roof is flat and in good condition.

In General questions | Asked By Chris Haun | May 10 10
15 Answers
Is it possible to eliminate condensation with insulation?

I was wondering if it was possible to insulate so much that the dew point actually occurs in the insulation? Also if this was to occur would it eliminate condensation or would it still occur within the insulation? I can see this as maybe being a possibility in a ceiling but would it be possible in a wall?

In Webinar Follow-up Q&A | Asked By Mick Paterson | Dec 23 09
0 Answers
New photos posted

When I published the blog on Jane Bindley's deep-energy retrofit -- the house on Squam Lake in New Hampshire -- several readers asked to see photos of the completed renovation. I recently received the photos, four of which I just posted:
A Leaky Old House Becomes a Net-Zero Showcase.

In Energy efficiency and durability | Asked By Martin Holladay | Jun 30 10
6 Answers
Oil vs propane - Need help with calculation

Oil $138,690 btu/gal, $3.02 gal, Furnace 75" efficient
Propane 91,333 btu/gal, $2.75 gal, Furnace 95% efficient
Then
Cost per "delivered" btu is
Oil: (138,690 x.75)/$3.024 = 34,397 btu's delivered per dollar
Propane: (91,333x.95)/$2.75 = 31,154 btu's delivered per dollar

So how many gallons of propane equals 1 gallon of oil after allowing for system efficiency?
Calc 1:
31,154X=34,397
X=1.1
so you need 1.1 gallons of propane to equal 1 gallon oil, so
$2.75x1.1=3.03
Which is about equal to the current cost of a gallon of oil

or is Calc #2 the right one to use?

Calc 2:

In Mechanicals | Asked By Walter Gayeski | Jun 21 10
9 Answers
Sill gasket for airtight drywall approach?

I am building a double stud wall house in Canada and have just finished the dense pack cellulose behind netting and preparing for ADA. I would like to use a gasket at all necessary areas (top/bottom plate, windows, doors, etc) behind the drywall instead of acoustical sealant to least interrupt the drywall installation i.e. we would put up all necessary gaskets ourselves and then the drywallers would just install as usual. Probably have them add screws every 8 inches to ensure full compression of the gasket and sealing of the joint.

In Green building techniques | Asked By Brian Mahoney | Jun 28 10
5 Answers
ASHRAE 62.2 2010

I saw recently that ASHRAE had published an updated ventilation standard for residential ventilation (62.2 2010) that is supposed to make fulfilling the standard easier for existing home retrofits, only I can't find out what the changes are. Rather than buying the standard myself, I'm wondering if anyone can give me a quick summary.
Thanks.

In General questions | Asked By Amanda Evans | Jun 29 10
5 Answers
Crawlspace ventilation or not; what is best for insulation?

I am building a workshop. The foundation is being built on bedrock (8 inch stepped foundation concrete wall with PT wood kneewalls to bring it up to floor joist level). The granite bedrock is sloped and therefore has surface water draining from the higher ground when it rains. The perimeter of the foundation (29' x 20') will have gravel and weeping tile.

There will be moisture present on the granite surface, regardless of my drainage plans.

My questions are :
1. Do I vent the crawl space?
2. What is the best way to insulate the the floor?

In General questions | Asked By mike | Jun 26 10
15 Answers
When air-sealing a house, does it always make more economic sense to make the house as tight as possible and then add mechanical ventilation or to air-seal down to some building tightness limit?

I'm working for an energy efficiency retrofit program. We have a very limited budget for our houses and therefore have been air-sealing down to the Minimum Building Airflow Standard (ASHRAE 62-89) so that we don't have the extra cost of mechanical ventilation. Is this flawed thinking? Is it usually in the economic interest of the client to air-seal as much as possible and then have the extra cost of putting in a vent fan?

In Energy efficiency and durability | Asked By Karen Leu | Jun 8 10
3 Answers
Post and pier foundation

Can I use a post and pier foundation in Michigan?

In Building Code Questions | Asked By Gary | Jun 26 10
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