GBlist: cellulose insulation

Bruce Sullivan (
Sun, 16 Feb 97 19:24:46 -0700

Forwarded by Bruce S. due to a technical problem

Hello, John Cruickshank here. Caught your question.

Have some comments re:

Date: Thu, 13 Feb 1997 17:07:38 -0700
From: Robert Seelig <>
Subject: GBlist: cellulose insulation; live roofs; TJIs; stem roofs and
foundations, etc.

I am working with a group in Moab, Utah who are designing and building
themselves a straw bale common house for a co-housing community. The
building s a 2500 square foot building using straw bales and timber
framing. The building will be entirely off the grid and powered by PVs
and hyrdo power. The building will be designed to maximize passive
solar efficency. We Have several questions:

1) Cellulose Insulation - How do you insure that there is an air space
for ventilation if one blows the cellulose in the cavity? Is an air
space necessary? How do you design to insure an air space?

>>Spec this as a requirement to the contractor. They have ways....

2) TJI - The maximize span of roof joists will be 24 feet. We are
considering using TJIs? Are there any other products that are
recommmended? What are they? Who are the suppliers. Note we are
considering installing a live roof, we need a product that can
accomodate the load of a live roof?

>>Do the math (DTM), ie: calculate the weight of the roof, and from that
select the right TJI.
(800) 223-5647

(800) 232-0788

(800) 423-2408

Trus Joist McMillan
(800) 628-3997

Willamette Industries
(800) 942-9927

3) Live Roof _ We are debating the pros and cons of installing a live
roof. We would like to discuss with anyone who has experience building
as well as living with a live roof what are the pros and cons. We are
especially interested in talking with someone who lives in a desert
environment such as Moab.

DTM ie: engineer the roof with the wet soil weight. I can be EXTREMELY
expensive to do long spans this way.

4) Stem Wall and Foundation - We are considerng using Faswall blocks
and we are wondering whether there are other products we should
consider. We would like to minimize the use of concrete.

Difficult to get an engineer to spec this out. Not too many have
with it.
I know a designer in Texas who may. Give em a call George Swanson, (512)

5) Used Cement Mixer - We would like to buy a used gas powered 4 to 6
cubic foot cement mixer. If you live within 200 miles more or less from
Moab, we would like to talk with you.

6) Heating and Cooling Equipment recommendations - while we will be
designing the building in order to minimize the need for auxillary
heating and cooling systems we anticipate the need for auxillary
systems. Are there particular manufacturers and models that people
recommend, why and how do we get information?

>>Wood heat for backup. Solar window exposure for most. May need a swamper
for cooling if there is no custodian to monitor opening and closing to
advantage of night cooling (close up during the day, open at night for
summer, reverse for winter)

7) Insulation - Is there other insulation other than cellulose that
people would recommend for the ceiling/roof. We are looking for items
which are cost effective and easy to install. We are planning to have
R-40 to R 50 insulation for the ceiling. We are also looking for
recommendations for rigid Board insulation.

>>Try out a stawbale roof. DOW makes as good a rigid insulation as any.
Do not design it in to interior space. Use it to the outside of the space
to minimize potential out-gassing problems.

8) We are also researching types of windows and doors. Are there
particular manufacturers people like or dislike.

Thank you,

Robert Seelig
Moab, Utah

Say HI! to Nicolas Brown for me.

John Cruickshank << Going Concerns Unlimited >> Hobbit House USA
Sunrise Ranch 5569 North County Road 29 Loveland CO 80538
Helping to get your concerns going since 1976
and provider of the "Sunny John" solution

Bruce Sullivan Tel: 541-484-9353
Iris Communications, Inc. Fax: 541-484-1645
Web: E-mail:
------------ 1,700 green building product listings online -------------

This greenbuilding dialogue is sponsored by Oikos (
and Environmental Building News ( For instructions
send e-mail to