Exterior siding question

[Paulaner]

Here in Maryland I have a 1700 ft2 1977 rancher that needs new siding. We have decided to use pre-stained cedar shakes on the front of the house (which is also about 40% recycled brick). We are thinking about using hardiplank on the sides (~26') and back (~72').

Picture of front:

We currently have 3/8" pressboard siding panels (?), and behind that is light blue rigid foam labeled "Total Wall Insulation Systems". The foam is about 5/8" thick for a total thickness of 1". The windows and doorframes extend about 1" out from the current exterior wall.

Picture of window frame:

The old pressboard siding has quite a few soft spots in various edges and personally I think it should be removed before we start the new siding. I don't want to spend extra money if it's not needed, but I want to make sure we have a quality job that we don't have to worry about 20+ years from now. Additionally I want to be certain that I don't lose any insulation, and would be happy to improve that where possible.

We are hearing different options from the contractors that have bid the job. One wants to pull the old siding and foam out, install OSB and tyvek, then cedar shakes or hardiplank. One says they can nail the new shakes / hardiplank to the existing pressboard, patching any soft areas as they go.

I'm a reasonably adept (inside the house) DIY guy. What I am thinking is to remove the pressboard panels, leave the blue foam installation, nail up ½" OSB, staple the recommended felt and then nail the cedar shakes. Depending on the about of time that takes, I may pay someone to do the hardiplank the same way.

What would you do?

Any recomendations are appreciated. Thanks.

[RicodJour]

You could go several different ways, and it all depends on the existing condition of the T-1-11 (that's what type of siding you have). Hardiplank can be nailed over the T-1-11, you can pull the T-1-11 and install the Hardiplank directly over the foam (you have to be more careful about over-driving nails and such with that method), or you strip the walls down to whatever's underneath the foam and start fresh.

I don't know why you'd want to remove the foam insulation, particularly with energy costs being what they are.* You probably should do a Forensic Siding Autopsy to determine what exactly you're up against. Remove one sheet of the T-1-11 in the worst condition and disassemble the wall checking for rot, mold and other signs of deterioration. That should give you enough information so you can determine how to proceed.

R

• Any guesses on how much a cord of wood will go up this year to take advantage of all of the other rising fuel costs?

[Colbyt]

Your plan sounds like the way I would do it.

Just make sure you won't encounter and problems around window and door projections.

Also keep in mind that any siding job is only as good as the window and door flashing that is under it. Caulk is NEVER a substitute for the proper flashing.

Colbyt

[RicodJour]

About two to two and a half times that around here..dumped. I imagine it will go up about 30% because of transportation costs and because it can.

R

[Paulaner]

I think the T-1-11 is marginal on most of the edges, so I'm planning on replacing that with 1/2" pressure treated plywood. I suppose I could use OSB, but my instinct tells me that it might be better to use the pressure treated stuff. The goal is to make it last 30+ years so I can avoid this kind of work during my retirement years.

I called a local insulation shop, and they will send a guy over to help me look at the current stuff and see if it's adequate. From what I can tell, the current foam looks to be R-5.

Thanks for your advice, Pauaner

• I have noticed wood pellets for my stove keep jumping up in cost every year.

[Paulaner]

Thanks Colbyt, great point. Looks like one window didn't have the right flashing, and carpenter ants found the moist wood inside the vinyl wrapped sill. Every job has it's tangents. Looks like I get to redo at least one window now.

Paulaner