INBAR performed a study to look at the feasibility of manufacturing a prefabricated house using bamboo panels. The study looks at some important considerations;
- Physical and mechanical properties
- Sound insulation properties
- Thermal transmission properties
- Fire resistance properties
- Cost analysis
We’ve interpreted aspects of the study to represent South African conditions and requirements in the post. Have a look, we think that the results merit serious consideration of bamboo panels for prefabricated housing projects.
Physical & mechanical properties of bamboo panels
This expanded table is reproduced from the report:
Product | Density g/m3 | Swelling % 24h in Cold Water | Swelling % 2h in Boiling Water | MOR MPa | MOE GPa | Compression Strength MPa |
Bamboo Panel | 1 | 2.5 | 17.1 | 135.78 | 10.50 | 71.99 |
OSB | 22 | 3.5 |
Some interesting points to note;
- The bamboo only swells by 2.5% when exposed to cold water for 24 hours
- The bamboo swells by 17.1% when exposed to boiling water for 2 hours
- The bamboo panel has a 83.79% higher MOR rating than OSB when tested using “BS EN 300:1997, Load bearing boards for use in humid conditions”
- The bamboo panel has a 66.66% higher MOE rating than OSB when tested using “BS EN 300:1997, Load bearing boards for use in humid conditions”
Flammability or fire resistance of bamboo panels:
The NFPA defines flammability rating according to a scale as quoted from this source;
This test method measures flame growth on the underside of a horizontal test specimen. The result is derivation of a Flame Spread Index (FSI)[2], which is a non-dimensional number which is placed on a relative scale in which asbestos-cement board has a value of 0, and red oak wood has 100.
The Life Safety Code groups flame spread ratings into five classes:
Class | Rating |
---|---|
A | 0-25 |
B | 26-75 |
C | 76-200 |
D | 201-500 |
E | over 500 |
Bamboo passes with a CLASS A rating (0-25).
If you study the table above, you will see that the bamboo panels have a flammability rating in the same class as Asbestos-Cement – impressive! Whilst Red Oak only achieves a CLASS C rating.
Preliminary cost analysis of bamboo based panel wall components
The exchange rate between the Yuan & ZAR is close to a 1:1 ratio, so the figures you see in the table in the report should be fairly close to SA figures. Please keep in mind that the bamboo panels used in this exercise are different to our Eco-Logic Bamboo panels.
Items | Unit price R/m2 | Subtotal | Remarks |
Bamboo panels (9 mm) | 40 | 8,800 | Double faces |
Wooden frame (40×60mm) | 4 | 880 | 5 meters is used for per m2 panel wall |
Adhesives, coatings | 22 | 4,840 | Including fire resistant coating for inner wall, water resistant coating for exterior wall, etc. |
Gypsum board | 10 | 100 | |
Wood processing | 5 | 1,100 | |
Painting | 18 | 3,960 | |
Total | 139 | 19,680 | Including test specimens. Total net areas of roof/wall panel components is 91.75m2 |