I’m not a pro just a semi-talented DIYer. My question is not about buildng but it is a carpentry related question that I think has the best chance of being answered correctly here. Can two layers of 3/4″ PT plywood be laminated and what is the best adhesive to use? I am considering polyurethane glue (?Gorilla Glue).
I an refurbishing our 1979 horse trailer that has two stalls in the rear for horses and a 5′ X 7′ dressing room/tack room in the front. I need to replace the floor in the dressing room area because some of the boards have rotted. The floor was originally 2X8 P.T. tongue and groove. The ends were inserted in the open side of a steel U channel welded atop the trailer frame. The boards rest on several pieces of 1/4 X 3″ steel bar on about 18″ centers. One problem is I can’t get the old boards out or new ones in unless I remove the entire trailer floor behind the area. I can cut the old boards with a Sawzall to get them out. I propose to make a new floor of two layers of 3/4″ P.T. plywood glued and laminated with SS screws on about 12″ centers to pull the two sheets tightly together.
Thanks in advance for any help offered.
Replies
I'm no cowboy but I know how those types of glue love to cure in the presence of moisture.
If the ply is dried after treatment-which most is --I would mist it down and spread like crazy.
Just wondering why you are making both plys treated and not just the bottom one?
Got a friend with a horse trailer and funny thing is is that he doesn' t have a horse--but he swears they are the greatest for moving and such.
Mike
Mike:
Thanks for your answer. I'm planning to use PT plywood for the inside (top) layer for additional rot resistance. I live in South Louisiana where it is hot and humid about 9 months a year and the trailer sits closed up most of the time in that atmosphere. I figured using PT inside would cut down of mold, mildew and rot on the inner surface. Also when in use at shows or just moving horses around there always seems to be spilled water buckets, muddy boots, and other wet smelly stuff on the floor and/or a window gets left open in a rainstorm. I am also thinking about trying to find a piece of heavy weight vinyl or similar floor covering to put on top.
Horse trailers can be useful to move stuff in an enclosed trailer. Some folks here use them to haul hay to their stables. Thanks again for your help.
Russ
Comment ca va.
Your plan sounds OK.Plastic resin glue (dry mix)would give you more open time,if you're going to have to do some fitting in place.
Seems like cypress used to be the norm down your way.I think 2x lumber would be more solid,but maybe not a concern with the steel framing.
But is there any concern with treated wood and horses' health?
Alphonse:
Thanks for your suggestion. Resin glue might be the best choice.
Cypress would be a good choice but it is really expensive if I could find it in 2 X tongue and groove. I can find it in square cut edges (still really expensive) but I want a solid floor with out gaps to keep water, dust and exhaust fumes from coming up from below while on the road. In addition to the mess, the dust and fumes aren't good for the horses. Also because the ends of the floor boards are inserted into the open edge of the channel and because of the trailer construction I can't get to either side to slide the boards into the channels so I can't figure out a way of putting in individual boards. To get the old ones out that weren't rotted I had to cut the boards with a Sawzall and pry them out from the center.
In the horse stalls for pure strength the best choice would be oak but it is not very resistant to rot and mold, especially in this environment. Pressure treated is best but you have to be very careful in your choice of lumber. So much of the PT southern pine on the market is not good lumber with lots of knots and weak spots that will break under a horse's weight. The other problem is that the new PT chemicals are apparently pretty corrosive and I have been told to only use stainless steel fasteners in it. Otherwise PT is OK for the floors because they are covered with thick rubber mats.
My plan is to make the floor in two sections and glue them together at installation. Sort of:
Right side: ______________ Left side: --------------------- __________ _________________
Laminate the two sections separately in the shop with glue and screws for clamping. Then slip one-half into the trailer apply glue to the overlapping sections, slip the other half in from the opposite direction and insert screws to pull the overlap sections up tight.
This is probably way more than you ever wanted to know about this project. Again, thanks for you help.
Russ
Just make absolutely sure that the horses can't get at an edge of the PT stuff to chew on it, etc.
DanH
Thats a good point. Thanks
Russ
How about putting something like Trex or the new engineered decking material down?
Thanks very much for the suggestion. That kind of product would solve the rot and mold problem, but locally the only way Trex, etc is available is in boards for decking and that presents the same installation problem as PT 2X6 in the dressing room area. I've ruled it out in the horse stalls because, it is my understanding, that the engineered "lumber" lacks the structural strength of real wood. I don't want to take that risk. You can imagine the disaster if a floorboard breaks and a horse puts a leg through the floor when you are going down the highway at 60 mph. Well chosen clear PT SYP 2X does a good job but it has to be carefully chosen and replaced at the first sign of weakness. Thanks again.
Russ