Subfloor Question

[MJBaldwin]

At my buddies hunting land we have a shack and it does serve the purpose we are looking for (a place to sleep) this was built by his buddies dad and never finished so wood was exposed for a few years (particle board of course because was the cheapest). This floor needs to be replaced soon. I am wondering how one can replace it. I haven’t been there since last season and plan to do a little trail trimming once the snow melts and could take a better look but want to think ahead I am going to try to attach a picture of what I think it looks like.

Thanks for help in advance

[YiGGiN4SLoBS]

If its just for sleeping and u dont really care about it for much else i would just get a sawz-all and a few blades and trim through the subfloor all the way around the bottom plate of the inside of the stud wall. Then get a couple good pry bars and a BFH a rip the bad stuff out with all the fasteners. (Hopefully the guy who built it didnt use ring shank nails and PL400 or your gonna be hatin' it!)

Otherwise you could always just put a layer of new stuff over the top of the old, just make sure fasteners are long enough- especially if your just using it for sleeping during hunting.

Just make sure the door clears it or if its even effected.

[MJBaldwin]

This is more the seating area when it gets late and we are all just talk'ing we have another area for sleeping. I was thinking of just ripping the old out my worry is where the wall sits ontop of it what do I do about that area. As stated I am not 100% sure that it does sit on the subfloor but almost positive it does. How could I shove another piece of wood in there. And I doubt he used those fastners your talking about it was the cheapest things possible for him.

[YiGGiN4SLoBS]

the only way to get that subfloor out from under the wall is removing all the screws in the bottom plate. probably 1 wall at a time and jacking up the wall so the weight is off the subfloor. Then, who knows if the subfloor is nailed to the joists underneath the wall. Sounds like a big can of worms to open up. i wouldnt worry about the wood beneath the wall if i were you, but its your project! good luck

Unless of course the stuff under the wall is so completely rotten you could just use a wood chisel or something to pound it out, i would just leave it.

[MJBaldwin]

So you would cut out the existing subfloor flush to the wall and then just lay new wood ontop of the existing floor joists?

[YiGGiN4SLoBS]

thats what i would do... I dont think you'll have to worry about the place collapsing if you leave that old subfloor under the walls. I havent seen the old floor joists. If they are rotten i would just double them up with some new green treated lumber. you may not even have to double every single one, maybe every other... Maybe the old ones are just fine. that will be for you to decide when you get the old floor opened up. Good luck with the project!

You may want to look into some green treated flooring to if this is an area with say, indoor outdoor carpeting or bare flooring that gets alot of snow or water tracked on it.

[MJBaldwin]

Yes it does I was thinking about getting some. What do you think the minium thickiness I should get is? I looked at 3/4 and really dont want to spend that kind of money on greentreated for this place if thats the case I read if you paint particle board wood it will last longer as well. But let me know the thickness your thinking! Thanks for all the help!

[BoxMN]

Heck for that type of building, I would just slap some 1/2" plywood over it, paint it, and call it a day Cheap quick and should last. I did that in my "old cabin" mainly to beef up the solidness of the old floor (guy would built it used only 12' long 2x8 as joists in a 12x20 shack) and then put in cheap snap together laminate over it. It is watertight building, but it feels a lot more sturdy now. Good luck.

[MJBaldwin]

Yea thats not a bad idea either for time purposes I just like to do things right the first time but this isnt really my issue but I hunt there and can use the land anytime and dont pay a dime so was thinking of fixing up a few things around there and making it better. Thanks for the information guys I will keep pondering it and think about which way to go.

My main concern was the plywood under the wall framing but sounds like both of you would just leave that so that was my main question!

[hawgchaser]

MJ,

I agree with several posters in that the results you desire can be fully realized without tearing up the existing floor. If the cabin is on a solid block or concrete foundation without much ventilation, plywood may well start to warp/separate without a moisture barrier underneath it. That may be part of the issue with the current particle board floor. I exclusively use a 3/4" (actually 23/32") T&G premium OSB for subflooring. It's about $30 a (4X8) sheet, but is so full of resins that water will bead on its surface. It won't warp or separate like plywood & you won't need an underlayment on top of it. JMO

[LightningBG]

There is no question, that if mine, I would just cover up what is already there with another layer of plywood/osb. Then maybe paint with porch floor paint or something or vinyl.

[Tom7227]

How old is the building? What does the thing sit on and is there ventilation in the space under the joists?

If the original guy was cheap he probably didn't use treated lumber. If so then the joists could be in tough shape particularly if the grade isn't set right with the rain running off the roof and pooling along the sides and then keeping the area under the cabin wet.

If the building is only around 15 years old and the floor is shot then I would be concerned about what is going on underneath. If it is more than 20 years old and the floor has just started to sag I would give some thought to just overlaying it, maybe even with just chipboard. If it lasted 20 or more the second layer will last at least that long and you won't spend a lot of dough and get into a mess.

The more you look the more you'll find and the more expensive and time consuming it could become.

[NoWiser]

MJ,

I agree with several posters in that the results you desire can be fully realized without tearing up the existing floor. If the cabin is on a solid block or concrete foundation without much ventilation, plywood may well start to warp/separate without a moisture barrier underneath it. That may be part of the issue with the current particle board floor. I exclusively use a 3/4" (actually 23/32") T&G premium OSB for subflooring. It's about $30 a (4X8) sheet, but is so full of resins that water will bead on its surface. It won't warp or separate like plywood & you won't need an underlayment on top of it. JMO

Yup, this. If the joists are ok get a real good subfloor and just go right over the old stuff. I'd use Advantech subfloor. It's a bit pricy but if you want to do things right, this is it. It absolutely won't absorb water and is a nice smooth surface that will sweep easily when it's time to clean the place. I'd stay away from plywood for the above reasons.

[MJBaldwin]

Well the building is probably only 5 years old but the guy left it open for the first year till I came around and wanted to help finish it. It's a deer shack that gets used three weeks out of the year so I'm not too worried about it sits on cinder blocks since its a no build area from what I know. It's not mine as its a buddies dads land. Just trying to put my dues in and help out since I hunt there and use it whenever I want. Thinking I will just put osb over the existing one. I would use the good subfloor you guys are talking about if it were a new building and I had ties to it but where I sit ill spend the 50 bucks to do the whole floor and that should work! Thank you all for your input made me really think about it though.

[Surface Tension]

Whatever you decide I'd look at keeping the moisture from the ground off the subfloor. Lay poly down on the ground. I didn't see if you mentioned anything about skirting but IMO it be best to leave it wide open. Air can pass through and less attractive to varmints taking up home under the cabin.

[MJBaldwin]

Thanks Surface Tension, Yes the shack sits about about a foot or so off the ground so air does pass through the bottom.

Thanks all for your input on this subject just have to find some time and get out there to do this project now.