Hardi or cedar lap siding over old T-111?
john_florida
| Posted in General Discussion on
I own a wood framed house located in west central florida. It is sided with T-111 which is 24 years old. I’m interested in siding the entire house with either hardi or cedar lap siding and wonder if I could just go right over the existing T-111 like they do with vinyl siding? The exterior is covered as follows: 1/4″ thermo board on the studs covered with tar paper then sheathed with the T-111.
Thanks for your advice,
John
Replies
I'm not familiar with "thermo
I'm not familiar with "thermo board" and how it might compare to the sorts of sheathing used elsewhere, but one point is that if you remove the T1-11 then you reduce the problems you might have around windows and doors with the trim getting "buried". (On the other hand, with only 1/4" sheathing and the T1-11 on standard trim you might be just about perfect if you apply Hardi over that.) If you apply vinyl you definitely want to leave the T1-11, though, as a nailing base.
You do want to evaluate the condition of the T1-11 and replace any "punky" pieces before you reside. (It should only be necessary to replace the bottom 2-3 feet, not the whole sheet.)
And you need to do something about the situation in that second picture where the siding is right down on the ground. There should be at least 4" between the bottom edge of the siding and the soil.
I think siding over T1-11
works pretty well, but you have to un-nail each window in order to deal with flashing it correctly (assuming they are nailed to the outside, rather than behind the ply). Might be worthwhile to start by nailing off the T1-11 on a shear nailing schedule.
Question?
Thanks guys. David, can you tell me what a shear nailing schedule is?
It's a nailing pattern required
to attain a certain level of "shear" (which is basically lateral stiffness). Required in earthquake country and I'm sure in FL too. Typical is 8d nails at 6" spacing at the edges of the sheet, 12" in the field. It's always given on the plans I get but there are also prescriptive values in the code.
T1-11 is often nailed with dinky little siding nails, and not many of them. Were it my house I'd nail the plywood off again before covering it.