Anyone used "Common Board" for their wood?

[23Sojourney45]

Hello knowledgeable people, I was looking at wood for my framing (skeleton) and came across "Common Board". The one I saw was 1 x 2 x 8, its light. I tried to research it online and it came back as softwood/pine. I was thinking of using it for my floor skeleton, since its light I may go 1 x 3 x 8 (which I think I saw as well). I will use foam insulation in the voids. Any thoughts on "common board"?

[TimC]

"Common" is a grade designation, such as #1 common or #2 common. #1 should be free of knots and cracks. #2 will have knots and some minor defects. I won't go into all the different nomenclature that the retail industry uses since some dream up marketing terms of their own.

See https://www.highlandhardwoods.com/lumber/lumber-terminology/

I'm assuming you are referring to wall construction. Floor construction is not critical IMO as far as the grade of the skeleton material. In the walls, avoiding large knots in the skeleton may be desirable as you fasten sheet material to the skeleton. It is not necessary, it's just easier to avoid splitting the lumber or having fasteners stand proud of the surface when driving screws, staples or nails. Is it worth the extra cost of "clear" lumber? That's up to you. If you accept that a random fastener may not sink in properly when it hits a knot then go for #2 common. Just be ready to have a method to remove the fastener or pound it in deeper with a hammer and spackle the hole if needed. If you are going for a nice wood finish on the interior or exterior surfaces stay with #1 lumber so you have less chance of a wayward fastener.

I hope that at least partially answers your question.

Some other descriptions I can think of include...
SPF (Spruce/Pine/Fir), these are softwoods.
Whitewood (softwood pine/spruce), often without interesting grain patterns. Occasionally just another name for #2 Common.
Standard, Quality, Select... Standard is probably closest to #2 Common, Quality has a few more "defects" such as knots, Select is closest to #1 Common with little to no defects. Menards uses this grade description on their 1" softwood lumber

[lfhoward]

In Home Depot speak, “select” is better quality than “common”. It’s true about the knots and the grain above. I wanted to add, common is often not straight, and tends to bend in weird ways when it gets humid. Building with select boards for your camper’s skeleton will be hassle free but more expensive for sure.

[23Sojourney45]

I'm assuming you are referring to wall construction. Floor construction is not critical IMO as far as the grade of the skeleton material.

Tim, I was just thinking of using it for my floor skeleton not the wall. I believe its spruce/pine/fir from HD and costs around $7-$8 for 1x2x8. It also has knots that you mentioned. So, its o.k to use these for the floor skeleton? I will also be screwing my walls into it from the side. I'm going to lay it flat so the 1" side will be the one I screw into. I wasn't sure if I should go with it or not.

[23Sojourney45]

In Home Depot speak, “select” is better quality than “common”. It’s true about the knots and the grain above. I wanted to add, common is often not straight, and tends to bend in weird ways when it gets humid. Building with select boards for your camper’s skeleton will be hassle free but more expensive for sure.

lfhoward, I was wondering if it would bend too. But, would it bend if its sandwich by the 2 plywood floor boards top and bottom? of course this will be after its glued/screwed etc...or will the weight of the two plywood prevent it from bending?

[lfhoward]

In Home Depot speak, “select” is better quality than “common”. It’s true about the knots and the grain above. I wanted to add, common is often not straight, and tends to bend in weird ways when it gets humid. Building with select boards for your camper’s skeleton will be hassle free but more expensive for sure.

lfhoward, I was wondering if it would bend too. But, would it bend if its sandwich by the 2 plywood floor boards top and bottom? of course this will be after its glued/screwed etc...or will the weight of the two plywood prevent it from bending?

No, once a wall sandwich is all assembled it will be rock solid. I used Kreg pocket hole screws with their jig, plus wood glue, to make the skeleton. Then I used wood glue, a nail gun, and screws to fasten on the exterior plywood.

But if you build part of your skeleton, wait a week before building a little more skeleton... and the humidity changes... You could be dealing with longer pieces that are not as straight as you want. The bending would happen before you build with them and before you lock them down as part of a unified structure.

[TimC]

Lauren is correct. Keep moving to get the floor fully assembled in a day or two. It will stay put once glued and fastened into a complete unit. Like Lauren, I used Kreg jig and screws to assemble the skeleton prior to completing the sandwich.

Just don't make the stupid mistake I made... description in post #4 in this build journal... https://www.tnttt.com/viewtopic.php?f=50&t=63575&hilit=+sort+of

You certainly can build the floor skeleton with #2 Common with some knots. Plan the assembly out ahead of time and eliminate knots on the edge if you can by turning the lumber around. If you can't avoid lining up a knot on the end where you will be fastening the wall just make a note on a post-it note attached to the frame on the area with the knot and avoid that area for fasteners for the wall.

Good questions. Don't be afraid to ask. That's what we are all here for...

Tim

[Tom&Shelly]

I used poplar for the floor, and it worked well. Not much more than #2 pine in cost, and much easier to work with (straighter). Only slightly heavier.

AC plywood is also a good choice. It may be pricey, but you can hollow it out and use it like boards, then the hollowed out pieces can be used for something else. Or, you can cut boards from the 4x8 sheet and use those.

Just a couple more options to consider.

Tom

[tony.latham]

I used both plywood and pine for the framing of my floor framing. The rear is solid since it needs to support galley vertical members, a 55-pound water jug, a 60-pound battery, and a 50-pound cooler.





The three skinny ribs are made from doubled 3/4" plywood set on edge to gain stiffness. The voids are filled with foam board, of course. The top and bottom are skinned with 1/4" subfloor plywood which I find is higher quality than 1/4" AC and a little cheaper. The plywood gussets are temporary to hold the parts in place while the other side is skinned.





Tony

[23Sojourney45]

No, once a wall sandwich is all assembled it will be rock solid. I used Kreg pocket hole screws with their jig, plus wood glue, to make the skeleton. Then I used wood glue, a nail gun, and screws to fasten on the exterior plywood.

But if you build part of your skeleton, wait a week before building a little more skeleton... and the humidity changes... You could be dealing with longer pieces that are not as straight as you want. The bending would happen before you build with them and before you lock them down as part of a unified structure.

Good to know. Yes, I'm planning on building the floor/skeleton etc...all in one go to prevent any warping/twisting unless some outside forces stop me lol.

[23Sojourney45]

Lauren is correct. Keep moving to get the floor fully assembled in a day or two. It will stay put once glued and fastened into a complete unit. Like Lauren, I used Kreg jig and screws to assemble the skeleton prior to completing the sandwich.

Just don't make the stupid mistake I made... description in post #4 in this build journal... https://www.tnttt.com/viewtopic.php?f=50&t=63575&hilit=+sort+of

You certainly can build the floor skeleton with #2 Common with some knots. Plan the assembly out ahead of time and eliminate knots on the edge if you can by turning the lumber around. If you can't avoid lining up a knot on the end where you will be fastening the wall just make a note on a post-it note attached to the frame on the area with the knot and avoid that area for fasteners for the wall.

Good questions. Don't be afraid to ask. That's what we are all here for...

Tim

Tim, thanks! I read your post as well, "Stupid" came to visit, yikes!! it happens to a lot of us...brain farts lol. But, guess what? those are the stories that we share and laugh about on here and in person when people ask about the build. Although, it wasn't a laughing matter at the time, they are stories. Knots are inevitable unless we get the more expensive wood and planning ahead of time is crucial. Good idea on the post it note.

[23Sojourney45]

I used both plywood and pine for the framing of my floor framing.

The three skinny ribs are made from doubled 3/4" plywood set on edge to gain stiffness. The voids are filled with foam board, of course. The top and bottom are skinned with 1/4" subfloor plywood which I find is higher quality than 1/4" AC and a little cheaper. The plywood gussets are temporary to hold the parts in place while the other side is skinned.


Tony

Tony, your 2 outside border/frame (the 2 long sides) of your skeleton are 3/4 thick laid flat correct? width of probably 4-6 inches? did you have problem screwing the walls to the 3/4? (I'm assuming you just screwed straight through the sheathing and through the wall into the 3/4 floor skeleton).

[tony.latham]

Tony, your 2 outside border/frame (the 2 long sides) of your skeleton are 3/4 thick laid flat correct? width of probably 4-6 inches? did you have problem screwing the walls to the 3/4?

Yes, flat 2x6" pine on the sides.

The walls are secured to the floor with PL3 adhesive, a line of pocket screws on the inside, and a second horizontal line from the outside.



The diagram is from my book but doesn't show the horizontal line of screws.



Tony

[23Sojourney45]

I used poplar for the floor, and it worked well. Not much more than #2 pine in cost, and much easier to work with (straighter). Only slightly heavier.

AC plywood is also a good choice. It may be pricey, but you can hollow it out and use it like boards, then the hollowed out pieces can be used for something else. Or, you can cut boards from the 4x8 sheet and use those.

Just a couple more options to consider.

Tom

Tom, yeh I saw poplar and like you said slightly heavier. I'm buying my pieces of wood but haven't bought the floor skeleton. I have been saying I want a 3/4" thick x 2" or 3" wide x 8 feet long skeleton frame. So, my walls will be screwed in straight from the outside-in but didn't know if the 3/4" floor skeleton would be thick enough for the screws to grab. I could add pocket screw like tony's but I was also going to fiberglass the outside and wrap the wall to the floor. Didn't know if that would be overkill by screwing straight from outside into floor skeleton, pocket screws from the top down, AND fiberglassing the outside. I could just screw straight from outside into the floor AND fiberglass the outside wall wrapping the outside floor.

[23Sojourney45]

Tony, your 2 outside border/frame (the 2 long sides) of your skeleton are 3/4 thick laid flat correct? width of probably 4-6 inches? did you have problem screwing the walls to the 3/4?

Yes, flat 2x6" pine on the sides.

Tony

New to wood working and all these measurements lol. So, 2 x 6? 2 inch thick and 6 inch wide Tony? for some reason I thought your skeleton was 3/4 thick flat on the plywood. I know there's nominal/actual measurements and I'm still trying to figure all of these out lol.