|
|
Home
|
|
by John B. Unger Murphy
Project & Location:
- Project Description:
- Historical Building
Renovation for Commercial and Multi-Unit Residential
New Construction walls and roof over residential wing of building
-
Construction Schedule as it relates to insulation, sheetrock, and moisture testing:
-
Application Moisture Content
-
Moisture Content Test
|
Moisture Measurements |
|
|
|
Test Location # |
Close to Inside |
Middle |
Close to Outside |
Cumulative Total |
Number of Measuring Depths |
Mean Moisture Content |
1 |
8% |
- |
8% |
0.16 |
2 |
8% |
2 |
7% |
11% |
13% |
0.31 |
3 |
10.3% |
3 |
8% |
- |
9% |
0.17 |
2 |
8.5% |
4 |
9% |
10.5% |
20.5% |
0.40 |
3 |
13.3% |
5 |
8% |
14% |
23% |
0.45 |
3 |
15% |
6 |
8% |
20% |
24% |
0.52 |
3 |
17.3% |
7 |
9% |
8.5% |
11% |
0.29 |
3 |
9.5% |
8 |
9% |
10% |
15% |
0.34 |
3 |
11.3% |
9 |
8% |
- |
8% |
0.16 |
2 |
8% |
10 |
9% |
- |
11% |
0.20 |
2 |
10% |
11 |
9.5% |
10.5% |
13% |
0.33 |
3 |
11% |
12 |
10% |
12.5% |
21% |
0.44 |
3 |
14.5% |
-
Moisture Content as it Relates to Time, and “Static” Moisture Content.
-
Buildings gradually achieve moisture equilibrium by releasing construction moisture during the first and second years after construction, achieving “Static” Moisture Content. Building moisture content will plateau at a relatively steady state of approximately 4% to 8% moisture, (special circumstances excepted). Building moisture content will increase during the humidity of summer, and decreases during the dryness of winter.
-
Table 2 compares moisture content at the time of installation, with the time of testing and with the building’s approximate “static” moisture content. Table 2’s time line gives information as to the speed at which moisture finds its way out of the applied insulation. To put this information into words: Moisture content at the time of application was 35% more than the building’s future “static” moisture content. Curing had occurred for 40 to 60 days prior to the date of testing. The spectrum of moisture content in the cellulose:
- Fifty-eight percent (all 2x6 and some thicker wall cavities) had cured from 35% down to within 3% or less of the “static” moisture content.
- Seventeen percent had cured from 35% down to between 4% to 5% of the “static” moisture content.
- Twenty-five percent had cured down from 35 % to between 7% to 9% of the “static” moisture content.
Time Line |
Day 1 |
Day 40 to 60 |
|
Day 360 to 720 |
Test Location # |
Installed Moisture % |
Mean Moisture % |
% Moisture yet to be released to reach Static |
Static Moisture % |
1 |
43% |
8% |
0% |
4-8% |
2 |
43% |
10.3% |
2.3% |
4-8% |
3 |
43% |
8.5% |
0.5% |
4-8% |
4 |
43% |
13.3% |
5.3% |
4-8% |
5 |
43% |
15% |
7% |
4-8% |
6 |
43% |
17.3% |
9.3% |
4-8% |
7 |
43% |
9.5% |
1.5% |
4-8% |
8 |
43% |
11.3% |
3.3% |
4-8% |
9 |
43% |
8% |
0% |
4-8% |
10 |
43% |
10% |
2% |
4-8% |
11 |
43% |
11% |
3% |
4-8% |
12 |
43% |
14.5% |
6.5% |
4-8% |
The damp spray cellulose does rapidly drop moisture content, even under adverse winter conditions and with interior sheathing installed (gypsum wall board). The remaining moisture will continue to decrease along with the rest of the structure’s building materials until equilibrium (“static” moisture content) is realized.
Cellulose and the installation methods used for this installation are safe and approved as Building Material Compatible. This case study is representative of the hundreds of thousands of structures being similarly insulate through out the USA each year.
|