Insulation for board and batten barn wall

[fishpick]

I have searched the forums and not found exactly what I'm looking for - so I figured - "hey, what's another insulation question"...

New pole barn - typical board and batten siding... complete with the charm of some cracks, splits and general leakiness (it's a barn!).

I'm planning on turning one end (about 18x30) into a wood shop... so I'm contemplating floor design now... but I also have to get the walls insulated.

I'm looking for thoughts, opinions and experiences in adding insulation / framing / whatever to an existing board and batten barn to weatherize it into a year round wood shop. When I think insulation - Dow board pops into the front of my mind... but won't what - or any other non-permeable insulation then potentially hold water between it and the exterior walls - making them start rotting? Or do you do the basement refinish technique and frame up a wall inside the exterior wall and vapor barrier it - allowing for an air space between the exterior boards and the insulated wall?

 

[inveresk]

Can you describe the existing construction. What's behind the leaky board and batten? Is there any building or tar paper to prevent water that gets behind the siding from reaching the structure? What is the board and batten fixed to - ply, stud wall, posts and rails?

 

[RPK]

If you put any type of insulation up against a leaky exterior wall it will only be a matter of time before you have major repairs from the water infiltration. It may not be much of an issue now because the water dries up on the inside of the wall being exposed to open air.

If you leave the siding as is you may be o.k. to add a wood framed wall on the interior leaving an air space of an inch or so to let the exterior air dry. Or better yet and maybe cheaper you could take off the batten strips and install a tyvek type barrier over the boards and add vinyl siding. Then the exterior wall would be water proof and you could insulate and finish the existing exterior walls

RPK

 

[fishpick]

It's a 6 year new pole barn... The exterior walls are really just the board and batten attached to the furring strips that run between the poles.
The rough pine was most likely still wet when the barn was built - and like all things - shrunk. So now some of the board have cracked or pulled slightly apart... it's common for this sort of construction to do that.

My reason for posting was really to see if anyone else has inherited a barn like this and what they did to make a portion of it a year round shop. I'm thinking that I will have to build new walls around the exterior to keep from rotting out the siding.

 

[inveresk]

RPK is right. If you insulate while water ingress continues through the board and batten, you'll stoke up problems.

You could construct some sort of insulated, stud and ply panels that could then be mounted inside the barn. If the panels were tar paper faced to prevent them from water damage, and you leave an air space between the tar paper and the existing board and batten to ventilate and drain the cavity, this might work but you'd need to direct any water that gets through the board and batten somehow back outside so it can't lie at the bottom of the cavity.

Or you could remove the board and batten where your shop is going and refix after you build new insulated outside walls.

As a point of information, in this neck of the woods the practice with board and batten (or any other siding) is usually to get it coated before delivery. It's then protected during storage and construction and doesn't shrink or warp nearly as much after it's erected. It's also cheaper than painting it once it's up. For example, it cost me an extra $325 CAD on a 2300 sq. ft. office and workshop to have all the board and batten and trim delivered with one coat of General Paints semi-transparent stain on all faces and edges.