303 T1-11 Fir
T1-11 siding is an economical siding option manufactured to resemble the look of a series of vertically positioned siding boards. The sheets of either plywood or oriented strand board (OSB), have grooves that run up and down the length of the board at intervals. A single sheet of material takes on the look of individual boards. Ease of installation and price makes T1-11 an attractive choice, but the board does have its drawbacks. If not properly finished and maintained, T1-11 board is notoriously susceptible to water damage.