Bathroom Floor Repair

[John Sims]

Need some advice on repairing a soft spot in the rear bath of a 71 international. Spot is aproximately 6" x8" located in the center of the floor between the sink and the closets.

Reading some of the other posts sounds a bit intimidating on the challenges of floor repairs. Would patching it be the best plan?

Thanks, John

[thenewkid64]

Hello John and welcome to the forum.

The first question is, do you know what caused the soft spot, and had it been remedied?

The second question is, how handy are you with a tape measure and a circular saw?

Patching the floor is not that hard, but I have one criteria on doing things to my Airstream ( Ok it is badged Argosy) If I am too intimidated by it I ask tons of questions here and read posts until I think I know it all. Then I proceed VERY carefully and attempt to do it myself. Now I am handy with a tape measure and a saw, but without a service manual to see what is beneath the floor I would be very leery of cutting into the floor. If the spot is really soft you could use a drill to punch thru and tear out by hand until you got to good wood, then get the saw out to cut to a frame member.

Let me expound.

The flooring needs to be cut back to the point that you are into good solid wood. Depending on the placement of repair there are two methods of patching. One is to cut the bad out, cut cleats and mount with screws and glue to the underside of the floor surrounding the fresh opening and drop into the opening a cut to fit piece and screw and glue it into place.

The other option is to cut the flooring back to the point that you are on a frame rail or floor joist and re-attach the new flooring to the frame itself.

In either case remember to set you saw to the thickness of the flooring only, or you may cut something that is VERY expensive to repair.

[Chas]

I would do a bit of probing around before cutting anything. Use a good heavy screwdriver and try to find the furthest extent of the soft floor as possible. I have seen the epoxy treatments but feel they don't have much structural integrity and therefore I don't recommend them. Just my opinion. It has been my experience that the flooring will rot from the underside and the edge of the walls, working it's way inward. Whatever rot you see from the inside is usually twice as bad from the underside. You may need to pull some of the cabinetry, toilet or shower pan to find the true extent of the damage. Or you can go from beneath, as long as there aren't any tanks in the way. You will also need to find any water leaks as that is what causes the vast majority of floor rot. I am currently repairing the floor in my Overlander which had ongoing water leaks for years before I had it. Pay close attention to the very perimeter of the floor, especially where the frame crossmembers terminate. If the flooring rots away at those points the entire shell can sag and settle unevenly, causing ripples and bows in the lower parts of the exterior skin. Yes, it sounds a bit scary but it is really just common woodworking knowledge and common sense engineering.

Good luck,

Chas

[j54mark]

I am really sold on Rot Doctor (www.rotdoctor.com, I think). However, while I am more confident about it than Chas, it and similar products do have their limits. Say half the wood has rotted away. Is it reasonable to think that simply hardening the remaining wood is going to make the resulting matrix (for it is not really wood anymore) as strong as wood of full thickness? It seems likely to me that the most optimistic result would be that it will be as strong as wood of equivalent thickness. Most likely it is somewhat less.

Rot Doctor treated wood can be surprsingly strong. One thing for sure, if you want to remove screws or nails, get them out before you treat!

Mark

[joel]

I have in the last year had a lot of chances to repair floors. I have a friend that sells used airstreams and sometimes he ends up taking some in trade that need repairs. I have heped with a few of them . I have some experiance with fiberglass work so we put it to use on the floors. On areas next to the walls and frame members that are not more than 6 to 10 inches deep into the interior and not more than 18 inches long can be fixed by dropping the bannana wrap and driving a sheet of aluminum or galvanized metal at least 1/16" thick between the frame and floor. Clean all old loose wood out and stores such as lowes have a product called wood restorer that hardens the remaining wood. I then take a dremel tool and bur and cut grooves in the good wood that lead straight across the hole and into the frame channel {Alternate the depth with 1 1/2 the depth of the wood floor and the next one 2/3 of the depth} . I lay 3/16 galvanized rod or stainless rod at about 2" intervals in these and into the channel. before you lay the rod in put 2 or 3 layers of fiberglass matting and resin in the hole lay in every other rod and put in more matting and resin . Lay in the rest of the rod and push down into the matting . Put in more of the matting and resin and let harden . Make sure to flow the resin into the grooves to set the rods firmly in place.Stop just even with the floor.You can sand it down if you need to . Last cover the entire patch with a single layer of matting and smooth the resin into it . Cover all the grooves with it . I have patched areas as large as 16" around in the center of the floor using the same process even across frame members. You just Have to be able to work a metal or piece of wood backer under the floor to keep the resin in place.
These patches hold an amazing amout of weight.And as I have several of them on my 73 includind one in the doorway With all the traffic and strain that it gets there I know they hold up pretty well.

The fiberglass kits with instructions can be found in the wood filler areas in the building supply stores or in auto part stores {same kits]. Good luck