More Building a Net-Positive House
Ben Bogie, project manager for the build GBA is following, explains how his team solved for the clients’ objective to reduce concrete in their foundation. The vapor-broken assembly consists of 18 in. of foamed glass from Aero Aggregates laid in 6-in. lifts, compacted and top-dressed with sand. We learn about the assembly’s R-30 sub-slab insulation value, spray-on waterproofing system, Stego heavy-mil. vapor barrier, and how the crew handled the transition between materials to ensure control layer continuity.
_________________________________________________________________________
Ben Bogie is a second-generation high-performance-building obsessive working as a project manager for BPC Green Builders of Wilton, CT.
Weekly Newsletter
Get building science and energy efficiency advice, plus special offers, in your inbox.
5 Comments
I had a number of questions after watching that video -regarding cost in particular. Most of them were answered when I googled them and landed back on this GBA article with some useful comments. An update regarding the current availability and delivered cost of Glavel in North America would be great.
https://www.greenbuildingadvisor.com/article/two-startups-seek-grow-interest-foam-glass-fill#:~:text=Glavel%20sells%20for%20between%20%2485,gone%20as%20far%20as%20Seattle).
I have had people ask me questions about what happens if there ends up being a lot of water from below in the foamed glass. I know-- drainage - but what if? does the R value go away?
I'd love to see some numbers on GWP for the North American produced cellular glass aggregates. Per this 2021 article https://www.greenbuildingadvisor.com/article/choosing-low-carbon-insulation cellular glass aggregate has a HIGHER GWP for a given R value than EPS, though seemingly corresponds to the European manufactured Glavel being shipped. Unfortunately Aero Aggregates website has nothing meaningful other than noting they use a recycled feedstock https://www.aeroaggna.com/sustainability
Nice air tightness and thermal bridge free design details.
Q1) A question on the use of a half basement (crawl space) instead of a full basement (added useable / treated floor space) or a frost protected shallow foundation and slab on grade?
The crawl space appears to be most of the cost of a full basement with none of the added space benefits? Was there some grading issues on the site that justified a crawl space vs slab on grade?
Q2) What is the Embodied Carbon of the foamed glass insulation vs that of EPS which is in the range of 288 kg of CO2e/m2 for 100m2 of R5.
https://www.buildersforclimateaction.org/report---nelson-material-carbon-emissions-guide.html
Q3) Does foamed glass install faster (less labour cost) then equivalent R value EPS?
When I asked for a quote on a price for replacing gravel with Glavel it came to approximately four times the price of gravel. Two things recommended it; the light weight and ease of installation, and the insulating value. Does the insulating value account for the air spaces and will the insulation value hold if the soil is saturated with water?
Log in or create an account to post a comment.
Sign up Log in