Community: General questions

Much of the value of this site is the pooled experience of members and their willingness to share it. This page offers a Community area formatted for Questions & Answers dedicated to General questions. Other topics appear to the right.

Anyone may ask a question and anyone may answer. Sometimes one of our 15 Advisors may chime in; in other cases, you'll get the wisdom of some of our members who have some experience in this area. We encourage everyone to give us the benefit of both their questions and answers. The usual rules of courtesy apply.

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1 Answer
Life Cycle Costs vs. Upfront Costs?

Can you direct me to any good information on showing how over the lifetime of a building ... sustainable design will save the owner money. We are working with a church congregation who believe that a sustainable building fits their values, however in order to move forward they would like to see real numbers/data on how the higher initial investment will benefit them in the long run.

Thank you for your time!

Asked By Whitten Architects | Aug 30 10
0 Answers
Communicating with other GBA members

I get requests at least a few times per week to help people get in touch with others within the GBAGreenBuildingAdvisor.com community. I always forward the notes to the appropriate people, and I'm happy to do it.

These requests make the need for a better community-building apparatus even more apparent. In the coming year we ought to be able to implement something along the lines of user profiles and user groups, but it's not at the top of our list of things that really, really need doing right now.

Asked By Daniel Morrison | Aug 27 10
1 Answer
Rafter tie question

Live in Maine have a colonial house with unfinished full attic, 8:12 pitch roof., 20 years old.

Looks like when roof was framed they basically decked over the floor of the attic (second floor ceiling) with plywood and then placed the rafters on top of this deck with a birds-mouth cut on edge. Ridge is non structural; no collar ties.

Asked By Christopher Redmond | Aug 25 10
60 Answers
High humidity issues in a spray foam attic

Have an interesting one here for you building science detectives.
Existing two story home built in the 1950s – Charlotte, NC (mixed humid) – approx. 3000SF. Existing mechanicals were a furnace in the crawl space with duct work distributed throughout the house and an air conditioner in the attic serving the second floor. Old batt insulation in the ceiling, wall insulation undetermined (we think none) and batts in the floor.

Asked By Danny Kelly | Jun 18 10
9 Answers
Relative importance of embodied energy?

I read this case study by David Fridley of Lawrence Berkeley National Laboratory:
http://www.theoildrum.com/node/6842

Then I remembered one of Martin's blog entries:
http://www.greenbuildingadvisor.com/blogs/dept/musings/energy-use-most-i...

The case study indicates that when evaluated on a annual basis, the embodied energy of a residential building is roughly equal to the energy consumed for its operation. The case study assumes a 30 year life-span for these buildings which is average in China.

Asked By Lucas Durand | Aug 21 10
6 Answers
What's the cost of excavating around the house perimeter?

I am planning on performing a retrofit of my 1950s ranch-style house to air seal and increase the R-value of the walls. I am planning on adding 4 inches of rigid foam on the exterior of the house. Part of the plan is to bring the foam down to the footings of the basement walls.

My question is this: What is a reasonable price to pay for excavating a trench, 6 to 8 feet deep by 2 feet wide, around the house? I have about 100 feet of basement wall that needs to be excavated. Can you give a $/linear foot cost?

Thanks.

Asked By jhoin | Aug 19 10
5 Answers
Temporarily for a few months -- Tyvek wrap or foam or both to protect a house?

I am having old asbestos shingles removed from my house. The roof is fine. The outside house walls will be then bare wood.

I am submitting docs to the Bldg Dept for permits to do a renovation project in a few months. What should I do to protect the house temporarily. Do I just put up Tyvek wrap? Do I do Tvyek wrap and some sort of foam?

Asked By Maria | Jul 27 10
12 Answers
Airtight Drywall Approach

I have been thinking about a strategy for improving the ADA. This may not be a new, but the idea is to install all exterior wall and ceiling drywall BEFORE any of the interior partitions are even framed. One could carry this further and tape, finish, and apply primer (VB primer in heating climates) as well. This strategy might best be used by custom builders.

Advantages
-drywall boarders should love this...think of the speed and ease of installing nothing but large sheets without any obstacles. Tapers and finishers should also love this.

Asked By Garth Sproule | Aug 13 10
11 Answers
How to attatch rigid insulation to old house - furring out window?

We are building a house in Northern Canada and I am not sure the next step. The house is 2400 sq. feet, 5/8" drywall, vapor barrier, 2x3 horizontal strapping with R-8 batts, 2x6 wall with R-20 batts, OSB sheathing, house wrap, and I want to add 2" rigid to the exterior of the house. The house has a HRV system throughout, electric baseboard heating, and the roof is R60 blow in. My question is in regards to how to add the rigid to the exterior of the house. Do I glue the rigid on, and then strap vertically through the insulation and to the house studs??

Asked By Randi | Aug 10 10
3 Answers
Does Polyurethane foam degrade rigid EPS?

I was planning on using Dow's Great Stuff polyurethane foam sealant to air-seal home-made EPS wind stops in my rafter bay ends to my roof deck & air chutes.

A salesperson at my local building store warned me that polyurethane foam would eventually degrade my EPS wind stops. I have been having trouble confirming this on Dow's website.

If this is true is there another type of sealant that would work better in this situation? Thanks for your help yet again.

Asked By Colin Kindrachuk | Aug 10 10