Posted 2009-04-02 4:45 PM (#102660) Subject: Help... I have a few questions on putting in a LQ floor/bed area.
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Posts: 241
This week end I'm going to tackle the floor and bed area of my LQ. My goal is to get the floor, shortwall and floor of bed area insulated and covered with plywood.
I'm a good builder and I have a nice shop/barn, so I think I can do it in two days without too much trouble. I ordered the DIY book (DVD) from the folks on this site, I think that will be very helpful (BTW, if you are doing a LQ yourself, this DVD is a must, its well done). I just have a few question for you all, to help build my confidence I guess. :)
Here's my plan-- any recommendations you guys have would be MUCH appreciated.
1.
Cut some fir striping and lay it out on the floor about four feet apart, and around all the edges. Glue the strips down to the aluminum floor with some type of poly glue from a calking gun (what glue is best Gard?).
As I'm gluing it down I will screw it to the floor using self tapping SS screws. I may have to do pilot holes, I will see if its needed. The screws are just going to stick out the bottom of the trailer I guess-- is this okay? Will they ever loosen up? Do I need to cut them off for any reason? How long of screws should I get?
I will do the same fir strips on the bed area and the shortwall, although on the short wall I will put them closer together, maybe 24 inches?
Also, on the shortwall I guess I will have to use the SS self taping screws from the outside in, then grind off the ends on the inside if they go through the fir strips. Sound right?
2.
After I get the strips done I will start the insulation. Here's where I have a question for you all. I was planning in using the foam board on the floor (you know the stuff, it comes in pink, blue or white, the white has a reflective surface on it). Is this a good way to go or should I use the flexible shiny stuff that comes in rolls? I thought I would use the roll up stuff on the walls but on the floor I figured the foam board might give some support to the plywood... Thoughts?
Okay, provided I use the foam board for the floor as I was planning, I will cut it to fit in real tight between all the fir strips I have glued and screwed to the floor. I think I will probably put several beads of glue between the insulation and the aluminum just to help ensure it stays in place. Now the foam board and the strips will be the same width so I should have a nice flat surface to start laying my plywood on.
3.
What ply material should I use on each of the three surfaces? For the floor I was thinking 5/8 ply, for the short wall I was thinking 5/8 ply, and for the bed area I was thinking of 1/2 inch ply. Does this sound good or would you recommend something else?
I thought I would go with ply rather than OSB because it seems to be a little stronger. Do I need a certain type of ply that will withstand moisture better?
I will cut the ply to fit in real nice using a cardboard template if need in the nose. I will use the same poly type glue to glue this ply to the fir strips and the insulation board. Now... Do I need to screw the ply to the fir stripping or can I use a small nail gun of the proper length and just nail it every six or eight inches?
Posted 2009-04-02 5:14 PM (#102665 - in reply to #102660) Subject: RE: Help... I have a few questions on putting in a LQ floor/bed area.
Expert
Posts: 1391 Location: North of Detroit, MI
Is that how the DVD says to do it?
5/8" plywood is going to be VERY VERY heavy. I have 3/8" plywood (I used bead board - it is grooved plywood) and that's added a bunch of weight to my trailer without factoring in supports and cabinets.
You might need that for the floor, but if you are going to add wood flooring material, go with something thinner.
I laid my frame foundation on the GN floor and did not fasten it down to the steel. I didn't add to the existing floor so I didn't do anthing there.
I built a frame on the jack wall and tied everything in to the supports on the GN floor so I wouldn't have to drill through the steel panels. So... can't help you with that.
I would screw all final panels to the furring strips. no glue. It came in handy when someone (not me) wrinkled a wall on the trailer. The body shop guy was able to unscrew the paneling and put it aside, remove the insulation and then do the body work.
The bubble wrap stuff is SUPER expensive. I reserved that for filling in around curved windows, curved areas between walls and ceiling. Buy your sheet insulation panels in the thickness that fits inside the framework supports of your trailer. Then cut your furring strips the same thickness. : ) I think I used 1 3/4 in the bed floor area (I laid 2x4s flat on the GN floor- hence 1 3/4" high); then 3/4 in the walls and ceiling. I also had some thinner stuff.
Think in terms of what size a sheet of insulation is. 4' x 8'. Try to arrange your furring strips to take advantage of even measurements so that you are not cutting so many pieces. 3 strips of 16" equals 48" or, 2, 24" strips.
I found that my trailer supports were NOT spaced the same distance apart!! I had to measure nearly every section - a big pain on the ceiling area.
Posted 2009-04-02 5:22 PM (#102666 - in reply to #102660) Subject: RE: Help... I have a few questions on putting in a LQ floor/bed area.
Expert
Posts: 1391 Location: North of Detroit, MI
Buy an assortment of lengths of screws. There is a trick to envisioning how support is given with screws... I don't think you need to glue the stuff to the floor first either. Maybe a few spots to keep it from creeping. Once you put your plywood down, the weight will keep everything in place.
Be sure to mark where your undersupports are so that you can screw down into them. The distance between supports depends on what size the supports are and what is going on top of them. There are actually computations used when considering span (length) and what dimension wood has to be to support a certain amount of weight without bending.
I can't imagine using anything less than 2x2s with 1/2-5/8" exterior grade plywood. supports 16" ... MAYBE up to 24" apart. But again, it depends on what you are putting OVER the plywood floor/osb floor. If carpeting then go thicker/stronger. If wood flooring, go with less thick - but close supports.
OSB is structurally stronger than the same thickness of plywood. The type of glue is VERY important. be sure to get EXTERIOR glue for all projects since the trailer will be subject to moisture / heating / cooling.
Posted 2009-04-02 10:16 PM (#102678 - in reply to #102660) Subject: RE: Help... I have a few questions on putting in a LQ floor/bed area.
Extreme Veteran
Posts: 406 Location: Minneapolis, MN
The only reason I can see to use furring on the floor is if you plan on running some wring under the floor....which I wouldn't recommend.
I used 1/2" pink foam board and 7/16" cdx plywood. I cut the foam and laid the plywood right over the top. Used #6 x 1 1/2" self drilling SSTL bugle head screws and fired them through the floor, at 8" spacing.
I used 7/16" OSB on the walls, as a base for my finish material.
When you say "shortwall", do you mean the front wall that makes the gooseneck? The bulkhead? If so, I furred mine out with 1" x 1". My "shortwall" had some bow to it so I had to scribe a number of them to get the bow out. I then used a poly construction adhesive and SSTL #8 x 1" flathead phillips screws and SSTL finishing washers.
Posted 2009-04-02 11:27 PM (#102681 - in reply to #102678) Subject: RE: Help... I have a few questions on putting in a LQ floor/bed area.
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Posts: 241
Originally written by wyndancer on 2009-04-02 10:16 PM<BR><BR><p>The only reason I can see to use furring on the floor is if you plan on running some wring under the floor....which I wouldn't recommend.
If it can be done without the fir stripping it would sure be easier. Is it as strong this way? Would I use a strong adhesive to help hold it all together?
Can I do it this same way up on the bed area (other than screws would need to come in from the bottom).
Originally written by wyndancer on 2009-04-02 10:16 PM<BR><BR><p>
<p>I used 1/2" pink foam board and 7/16" cdx plywood. I cut the foam and laid the plywood right over the top. Used #6 x 1 1/2" self drilling SSTL bugle head screws and fired them through the floor, at 8" spacing.</p>
Is 7/16 strong enough? If so, the weight savings would be nice. I plan on putting a synthetic laminate on the floor when its finished.
Originally written by wyndancer on 2009-04-02 10:16 PM<BR><BR><p> Used #6 x 1 1/2" self drilling SSTL bugle head screws and fired them through the floor, at 8" spacing.</p>
Can these screws be picked up at Lowe's or Home Depot, or do one need to get them at a specialty store?
Originally written by wyndancer on 2009-04-02 10:16 PM<BR><BR><p>
<p> I used 7/16" OSB on the walls, as a base for my finish material.</p>
On the walls I'm doing tongue and groove. Will I attach that to the fir stripping, or should I put some OSB between that and the fir stripping?
Originally written by wyndancer on 2009-04-02 10:16 PM<BR><BR><p>
<p> When you say "shortwall", do you mean the front wall that makes the gooseneck? The bulkhead?
Yes, I never know what to call that wall under the bed area. Is short wall correct?
Why do I need fir striping on this wall but not the floor?
Should the strips be about 16 inches on center? Vertical or horizontal?
Posted 2009-04-03 7:34 AM (#102682 - in reply to #102660) Subject: RE: Help... I have a few questions on putting in a LQ floor/bed area.
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Posts: 151 Location: Manitoba, Canada
my concern with laying the floor over a foam board insulation without furring strips is that the floor wood compress over time -- and likely unevenly. I'd be willing to try it in the bed/gooseneck area, however. There's less wear and tear in that area.
Help... I have a few questions on putting in a LQ floor/bed area.
