Tartan Homes Sub-Floors
There have been some recent posts to local new-home builder blogs about sub-floors. Durability, appropriateness for hardwood flooring, and future squeaking are amongst the concerns that are being discussed. Some people are suggesting that the current sub-floors used by some builders are of an inferior quality, and that buyers should request an upgraded sub-floor.
I’d like to help clarify things regarding the type of sub-floor that we use at Tartan Homes, and why we don’t offer an upgraded sub-floor.
An important component of the overall floor assembly is the type of floor joist. If anything is ever going to squeak, it will be the joist, not the sub-floor itself. We use an engineered floor joist that looks kind of like a wooden I-beam. While they are not squeak proof, they are far less susceptible to squeaking than the traditional 2x10s and 2x12s that we’ve used in the past. Please visit http://nascorbykott.com for more information.
For the subfloor itself, in the spring, summer and fall, we use a 5/8” OSB board. The board has greater water repellent qualities than standard plywood, and meets or exceeds all the structural and acoustical requirements of the Ontario Building Code, as well as all the manufacturers’ requirements of the finished flooring materials that we use as standards or as upgrades. For areas with ceramic tile, we install an additional layer of OSB board. Ceramic tiles will not adhere to a surface that has anything more than minimal spring, and the concrete board facilitates this.
In the winter, we use a 5/8” ‘stable edge’ OSB board. This board is the most water repellent manufactured wood panel board on the market. It is far less susceptible than plywood to deterioration due to water or snow exposure during construction. Furthermore, unlike other boards, the tongue-and-groove joint will not swell or bulge as a result of moisture or temperature changes. Visit http://www.stabledgeosb.com for more information.
Both our structural engineer and our acoustic engineer advise us that a moderate increase in the thickness of the board will not provide a significant increase in either structural strength or sound attenuation.
An additional important component in the assembly of a solid and durable floor is the construction technique. At Tartan, we glue and screw the sub-floor onto the joists at initial framing. Prior to the installation of the finished flooring, we add an additional course of screws to ensure exceptional adhesion.
Finally, the durability of hardwood floor depends a lot on the humidity in the home. Broad swings in humidity can cause cupping and shrinkage. At Tartan, we offer hardwood as a standard in some rooms, and many of our purchasers elect to purchase hardwood for other rooms. We install a central humidifier and an HRV in every home. Besides ensuring a steady supply of fresh air, and reducing home heating costs, these two standard components of the heating system, when properly used, keep the indoor humidity at the levels that are recommend by the hardwood suppliers.
Like other builders, Tartan speaks about flooring as an ‘assembly’; each constituent part is considered in relationship to the whole, and to the method of assembly. We believe our flooring assembly uses materials and techniques that are equal or superior to those used by the very best of our competitors. For this reason, we do not offer upgraded sub-floors or floor assemblies as an optional upgrade.