Let's talk about tulip poplar for siding

Tony Sawmill · February 15, 2024, 07:31:50 AM

Hi all,
I am building a covered bridge on my property. I have numerous tulip poplar logs that I am thinking of milling with my sawmill to make board and batten siding. I have read that tulip poplar is better to install as board & batten as green lumber as long as nailed properly with the board nailed down the center and battens not nailing through the board behind it so that the board can still move and the battens keep the edges from cupping. Any practical experience with nailing up green tulip poplar board & batten siding? would love to hear the good and the bad and any tips/tricks for this species and application.

Don P · February 15, 2024, 08:15:30 AM

Yes, now I borate it, dry it, plane it, then attach as you describe.

beenthere · February 15, 2024, 10:38:45 AM

Quote I have read that tulip poplar is better to install as board & batten as green lumber as long as nailed properly with the board nailed down the center and battens not nailing through the board behind it so that the board can still move and the battens keep the edges from cupping

Tony
Good advice. Hope to see your covered bridge build.

Wlmedley · February 15, 2024, 11:50:00 AM

I built a woodshed last year using green poplar and nailed as you described.Put boards together tight and waited approximately 3 months before installing battens.Wood dried pretty fast and had probably 1/2" gaps between boards at that point.Had none or little shrinkage after that.I used screws to attach boards and battens . I think it turned out pretty good but as DonP said would have been nice to dry and plane boards before using although you would need to leave a space between boards to allow for batten fasteners

Magicman · February 15, 2024, 02:05:04 PM

Install the pith side of the boards toward the weather and chamfer the inside of the bottoms ~30° to make a sharp drip edge on the bottom.

This prevents water from wicking, wetting, and rotting the bottoms of the boards.

PoginyHill · February 15, 2024, 03:06:19 PM

I build a large shed with poplar B&B. Not sure how old it is, maybe 8yrs? Anyhow, I installed it as you mentioned, and it's been fine. I'll take a picture when I get a chance.

YellowHammer · February 15, 2024, 03:20:04 PM

My barn and many others near me are built from tulip poplar, which is the wood of choice because it is virtually impervious to wood boring insects here, including termites and carpenter bees.

I put mine on green off the mill, and the batton the next day before the siding had a chance to warp and bow. Nails in the edge of the vertical boards to maintain straightness, and then nails through the battons into the framing lumber, but not through the poplar siding. There is still little cup, but no rot and it's been there for a couple decades and the original siding on the barn was install 1979 by the previous owner. No sealant or finish, it just does fine.

Magicman · February 15, 2024, 07:35:42 PM

You want enough roof overhang so that you do not get any rain runoff spatter on the bottoms of the B&B. Chamfering the bottoms as I mentioned above will help to prevent the bottoms from staying wet and rotting.

KEC · February 15, 2024, 09:51:41 PM

My father told me many, many years ago that a lot of different kinds of wood can last a long time if you build a good roof overhang and arrange for the water to run off/shed. The people who built my house did not do this on some parts of the house. The rot confirms Dads' advice.

YellowHammer · February 15, 2024, 09:57:14 PM

Poplar siding is not rot resistant and needs to either stay dry, or needs to be able to dry out.

Large eaves, good drainage, lots of sun and wind exposure, stuff like that.

When I ran my siding to the ground, within a couple years, it naturally trimmed itself to just above ground level by rotting off. It looks perfectly trimmed now.

Tony Sawmill · February 15, 2024, 10:39:28 PM

thanks all for the replies- good to see I am tracking in the right direction. The 30 degree cut @ the bottom edge is something I would not have thought of but makes sense!
Thanks so much for all the insights everyone.

Magicman · February 16, 2024, 06:48:27 AM

Actually Sweetgum will also make siding but precautions have to be made as described above.

Yes Tony, with the chamfer on the backside of the lumber, water runs down the boards and drips off of the sharp edges rather than wicking back under and wetting the entire bottom of the board.

Rhodemont · February 16, 2024, 04:31:55 PM

I am going to be using ash for the walls on my garage/barn build. Have marked the 30 deg on my plans.

GAB · February 17, 2024, 02:26:50 PM

Quote from: Magicman on February 15, 2024, 02:05:04 PMInstall the pith side of the boards toward the weather and chamfer the inside of the bottoms ~30° to make a sharp drip edge on the bottom.

This prevents water from wicking, wetting, and rotting the bottoms of the boards.

Lynn:
In an edge view of the board, is the 30 degrees from the horizontal (or bottom edge) or vertical surface?
GAB

Magicman · February 17, 2024, 06:10:07 PM

~30° chamfer on the bottom edge leaving the sharp edge on the weather side of the boards & battens. Water runs down the boards and drips off of the sharp edge without wicking and wetting the bottoms of the boards.

I have no idea how to explain it any better than that.

Don P · February 17, 2024, 06:31:00 PM

I bevel the bottom edge at 15 degrees but run a horizontal critter crack blocker, then the battens to the bottom of that.

mike_belben · February 17, 2024, 06:42:14 PM

Brilliant lynn

GAB · February 17, 2024, 07:23:42 PM

Quote from: Magicman on February 17, 2024, 06:10:07 PM~30° chamfer on the bottom edge leaving the sharp edge on the weather side of the boards & battens. Water runs down the boards and drips off of the sharp edge without wicking and wetting the bottoms of the boards.

I have no idea how to explain it any better than that.

Thanks.
GAB

KEC · February 17, 2024, 07:28:53 PM

I rebuilt an old garage at the first house that I owned and sided it with board and batten. I looked at it after a new owner took posession and they had thrown yard waste right up against the back wall. I had to explain to her that that would cause the wood to rot. I've seen many expensive houses where a landscaper threw wood mulch up against the foundation AND the siding. I told the homeowners that the mulch holds moisture and harbors every species of bacteria and fungi known to decompose wood. And that if they did not get any benefit from my visit beyond my telling them to get the landscaper to pull that mulch away, then they got a good deal. I've seen 300K$ houses with rotted sills from this.

Magicman · February 17, 2024, 07:51:26 PM

I have the bottom lath near the bottom of the boards which will serve a critter shield but I do not stack the boards on anything. I do not want water to be trapped anywhere which would lead to rot.

Tony Sawmill · February 19, 2024, 08:20:26 PM

Thanks all for the insights- I appreciate it greatly!

PoginyHill · February 21, 2024, 07:16:57 AM

Here is my shed. Siding (both boards and battens) are quaking aspen. Not tulip poplar, but the wood is similar.

Magicman · February 26, 2024, 07:25:32 PM

@Tony Sawmill. I had an occasion today to see a Cypress Board & Batten sided home that was about 15 years old. The builder sorta used the method that Don P showed in Reply #15 above. I only took these 3 pictures but the entire siding job was a mess that could have been prevented.

The reason that I do not use this method is because by capillary action, moisture is drawn under the boards and remains trapped thereby rotting the bottoms of the boards.

The "ledger" board on the bottom was tapered downward but I had no way of measuring the angle.

I would prefer to make the chamfer on the bottoms of the boards as I described above, use a ledger board to insure that all of the boards are the same length and then remove it after the siding job is completed. The bottom lath would be treated and rest on the bricks. (I actually would prefer to use metal flashing in this instance.) That would give you about an inch for water to drip off of the boards and run off. The chamfer would prevent the bottoms of the boards from ever getting/staying wet.

Don P · February 26, 2024, 07:43:46 PM

That is a pretty good bit different than what I showed but I understand your point. I'm making a tradeoff to seal the gaps between the boards behind the batten. I'm not understanding how you are doing that?

Magicman · February 26, 2024, 08:22:26 PM

I am not. Since there is no gap between the boards when they are installed shrinkage will never be enough to matter and critters can't get in. As you mentioned, we make tradeoffs to accomplish what we think is best.

I was alarmed when I saw that mess this afternoon and I don't have a good solution. Maybe use a 6" ledger board with flashing? The house is vacant and this surely will affect the selling/buying price.