Using poplar to frame up a house.
nilst
| Posted in Energy Efficiency and Durability on
I’m ready to frame up my two story, 1450 square foot house. I can get air dried poplar 2×4’s for very little money. What are the pitfalls of building with Poplar?
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Why do you want to build with poplar instead of the far more common SPF (spruce/pine/fir) used for regular dimensional framing lumber? Poplar is probably the cheapest of the hardwoods, but it’s still a lot more expensive than SPF, is available in far fewer sizes, and probably won’t be in stock anywhere in sufficient quantities to build a house. Aside from the cost and availability issues though, I don’t see a problem EXCEPT you wouldn’t be using what is specified in the span tables (and other parts of the code), which is probably going to be an issue at inspection time, and possibly also for loading issues. You’d need to engineer everything in that case, since you wouldn’t be following the prescriptive codes.
Bill
My guess is the poplar is ruff sawn so it is literally 2 inches by 4 inches before it started drying. After it dries it will be smaller but still larger than the normal 3.5 X1.5. The woods thickness will have more variation when walls were plastered it did not matter as the plaster evened this out not so much with drywall. Ruff sawn lumber is considered a fire hazard in modern construction.
If this building will be inspected using this wood will make your life a living hell.
Poplar rots very quickly if you allow it to get wet.
Note most home insurance policies are based on a home built in compliance with the current code when built inspected or not.
Walta
Walta,
"Ruff sawn lumber is considered a fire hazard in modern construction"
Can you expand on that a bit? it's not something I've ever heard.
I could be wrong be it seems like common sense that the ruff surface is easier to set fire to than the smooth surface of construction lumber.
Walta
Walta,
The flame-spread ratings developed by the Canadian Wood Council don't distinguish by surface finish - and flame spread would only be an issue if the framing were exposed
It does make sense that rough-sawn wood would be easier to set fire to than smooth-planed wood, but it's not something I've seen quantified or as part of any building codes.
Plaining that much wood and radiusing all the edges seems like a lot of added cost if the only advantage is carpenter are less likely to get splinters. LOL
Walta
If the sawmill has a stamp it could be code compliant, but a quick search finds no structural numbers for poplar.
Assuming you mean yellow poplar, the wood of the tulip poplar tree, its engineering values are similar to or higher than those for eastern spruce or even Sitka spruce. (https://www.matweb.com/). It is prone to rot but as long as you don't take years to build your house that shouldn't be an issue. I've never heard of rough-sawn lumber being a fire hazard; I have used it occasionally including on two recent projects. The biggest challenge will likely be about inspections--who is grading the lumber for quality, and will your building inspector care?
I think the poplar that grows here is white. The wood is very white. My brother in law is stuck with thousands of board feet of poplar he doesn't need hence the question. I have heard that it can be difficult to drive nails in dry poplar. I don't know what it will do as it dries. Does it shrink more than SPF, does it warp more or differently than SPF and does it hold nails well? My joists are all from white pine roughly my age (70) 3x10s so I'm not worried about spans. The propensity to rot is common for all wood and I try to design for the possiblity of wetting from without as well as from within. I guess I will have to get a moisture meter so I can avoid problems that come with rough sawn wood that hasn't been graded. I suspect I won't see any inspectors. They are kind of rare around here. I asked the sawyer to saw the wood at 1 3/4 by 3 3/4 so I expect it to dry at close to 1 1/2 by 3 1/2.
Poplar being more rot prone than other woods means you have to be more careful about closing things in quickly, to protect the material. You have to go by the span tables per code, there really isn't any flexibility there unless you want to engineer everything, which gets expensive.
Your best bet might be to build the load bearing structure with regular SPF dimensional lumber, then use your poplar for architectural details where grading and inspections won't be as much of an issue. You could use the poplar on the floor (note that it doesn't take stain well though), walls, etc. Your argument to the inspector then is "my house will stand up, because the structure is all built the normal way, with normal materials. My custom poplar planks are just used for the finished floor, some walls, etc." That's probably a much easier argument to make to get things passed if there are any questions about your materials.
I haven't had any issues with nails going into poplar. I didn't find it any more prone to splitting than SPF. It drills pretty easily, and machines about the same as SPF too. As hardwoods go, poplar isn't very hard. I've build mostly simple furniture-type things with poplar, such as some baby gates and baby barriers, some kid-sized clothing racks, stuff like that. I leave them either unfinished (just sanded smooth), or paint them with my sprayer. I've not found poplar to be any more difficult to work with compared to pine, but it will dent easier than other woods that you'd think of as "hardwoods", so keep that in mind in terms of durability if you use it for any areas subject to physical wear.
Bill
Like Maine_Tyler said, it sounds like aspen--populus tremuloides (quaking aspen) is a common species. Here in Maine it's called "popple" which helps differentiate it from the wood of the tulip poplar (Liriodendron tulipifera), which is common for interior trim but has a pronounced green color when new, and changes to a chestnut brown in the presence of UV light.
I only have one experience working with "popple" and that was as trim 30 years ago. I don't recall what it was like to work with. Having cut a lot of small-dimension aspen trees on my property, the wood seems to be weak and brittle, but that might change as the tree grows.
Different species of wood have wildly different propensities to rot; black locust, for example, is nearly rot-proof even in direct ground contact. Poplar (and popple) are among the least rot-resistant woods. But as long as you're keeping the wood dry, it won't rot.
I see you're in Quebec. Your poplar is likely aspen of some kind.