Suggestions on replacing hayloft floor...

[amstaff]

Just last month we had a major barn renovation completed by a contractor. One of the things that was not done, however, was the replacing of the hayloft floor. The old roof leaked for many years before we purchased the property, and the center of the plywood floor has some rot in it. Not rotted to the point of possibly falling through it while walking on it, but rotted nonetheless. Contractor said to just nail plywood over the exsisting floor...

I'm looking for feedback on how other people would do this project because I'm probably overthinking it!

My first thought is... Is simply nailing plywood over the exsisting plywood taking the easy way out, or is this how it is usually done?? I'm not sure the top (new) plywood would attach all that well down the center of the loft because the floor does have some rot in it. Attaching everywhere else would be fine, though. Would 1/2" plywood be fine (current floor is 1/2")??

My second thought is... Would it make sense to completely rip out the exsisting floor and replace with 3/4" plywood??? This seems like a lot of work, not to mention it would be considerably more expensive then option #1.

Lastly, if I can get away with just putting a new layer over the exsisting floor, would OSB be appropriate? It is a well ventilated and dry hay loft...

Any help would be great!!!

Thanks,

Amstaff

 

[5030]

Forget OSB. It's damp in a barn and OSB won't tolerate dampness. I had exactly the same scenario a few years back but I re-did the barn myself.

I replaced the bad floor supports (pegged and tenoned) with pegged 40 retentioin PT timbers of necessary load bearing size (bigger than the original) hardwood timbers.

I used pre turned hardwood doweling for the pegs. Part of the floor was useable so I left it and overlayed with 3/4" 40 retention PT BC Plywood over the bad sections and the good. The I laid on sheets of 1/4" BC plywood as a top layer. You don't want the 40 retention wood in contact with any feed stufs like hay.

Mine has been done over 10 years now and it's as good as when I put it in.

I used Galvanized square drive deck screws throughout.

Barn restoration is expensive if you don't do it yourself....

 

[2458n]

OSB tends to swell when exposed to high humidity. I would believe the Contractor knew what he was talking about. Leave alittle space between the new sheets of 1/2 as they will buckle when nailed tightly end to end. If it is like some barns around here you may have to redue the floor in 100 years.

 

[5030]

OSB tends to swell when exposed to high humidity. I would believe the Contractor knew what he was talking about. Leave alittle space between the new sheets of 1/2 as they will buckle when nailed tightly end to end. If it is like some barns around here you may have to redue the floor in 100 years.

Swell and seperate. I neglected to state that I used a couple 10 D nails to space my plywood as I laid it down. All wood expands....

 

[BeezFun]

If it's structurally sound, what is your goal covering it up? Is it just aesthetics? If so you might just think about painting it. I like white on the inside of barns, it makes it easier to find things because of all the reflected light. If you cover it with something, make sure there's no mold started. Covering it up could give it a nice environment to grow.

 

[amstaff]

Great info. Thanks!


I wouldn't say the floor is structurally sound... it just isn't to the point where you would fall through it (yet!). If I applied enough pressure, I could definitely put large holes through it - down the entire center of the loft. It definitely needs repaired/replaced.


Because of the swelling mentioned, tongue-and-groove is probably not the best choice... I'm glad I asked this question, because I was thinking about T&G as an overlayment or new floor!

Amstaff

 

[Pete Judd]

Amstaff, I don't know where you are at but a couple of guy's around here in the PNW are selling old growth 2x6 fir boards taken out of an old pipeline built around the 1930's. They are treated all the way though, and are between 16 and 20 feet long. The are getting 2 bucks a board. They have a slight cup but that can be taken out if needed. They would make a great strong floor, cheaply. I have a friend building raised bed gardens out of them, and I will be using them for the new pump house and the shed for the attachments. Won't root out, but if they ever catch on fire, I think you would never put it out.

 

[amstaff]

I'm in Central PA... Happy Valley!

 

[Pete Judd]

Amstaff, it would cost a bunch to get it to you, but see if you can find a local sawmill, that sell rough sawn 2 by's. I should be fairly cheap, as no one is building houses right now. We have several small mills around here that are having a hard time paying their workers, so the prices have dropped.

 

[billybobjimmyjoejack]

If your current floor is 1/2" just remove the rotted areas and fill back in with new 1/2". If it is easier to remove a whole sheet, when just part of it is rotted then I would do that. Save some time and money by just replacing the bad areas.

 

[amstaff]

I have an Amish mill not far from my house that I have purchased a lot of wood from... they do Pine and Hemlock... something to consider.

 

[amstaff]

If your current floor is 1/2" just remove the rotted areas and fill back in with new 1/2". If it is easier to remove a whole sheet, when just part of it is rotted then I would do that. Save some time and money by just replacing the bad areas.

I have thought about this, but there are some weaker areas at each gable end that I would want to replace while I am doing the rest of the floor... I would end up removing close to 2/3rds of the floor.

Covering everything with 1/2" plywood is looking beter and better! Thanks for all the responses.

 

[forgeblast]

I have hemlock as my floor, 2x6 i think. Still in great shape.

 

[BeezFun]

Covering everything with 1/2" plywood is looking beter and better! Thanks for all the responses.

From your description of the size of the areas that are weak and the severity, you might consider whether 1/2" is strong enough for a hayloft. If you get a big guy carrying an 80# bale of hay, the floor needs to be solid. You didn't mention what the joist spacing is, might be better to put down 3/4" T&G subfloor to cover everything, that would get you back to a solid floor. Make sure the existing design can handle hay and another layer of plywood.

 

[USNative]

You may want to check all the supporting floor joist's as well, could be some dry rot there. I would go with 3/4" plywood on any floor.

There were some comments made on OSB being prone to moisture and it is if its not protected. I used it for all my stall walls in my new barn and it will hold up if you keep it dry. In my previous barn I installed it 11 years ago and it still is as good as the day I put it in. You have to keep air space between it and the ground though because if you don't it will wick up moisture and then the rotting process will start in short order.

If you ever use OSB for anything be sure to cover it with paint. Really helps it withstand the elements. I would not recommend it for flooring in a barn though. My new Tack Room has 3/4" tung & groove for flooring and will be covered with flooring material as well.

OSB is very cost effective and if it's properly used it will last a good long time. Hope this helps.