Hardware & Soft-Ware

Considerations

Each vehicle is different and the materials I used are for my 2016 Ford Transit MR LWB.

The plywood floor has to be secured to the vehicle, as it also functions as a base for all the cabinets and appliances in the van. In case of an accident, you have to make sure that everything stays in its place.

I used two techniques to increase the hold of the floor. The first is using rabbets/dadoes along some of the plywood edges, where each sheet adds holding power over the other sheet, to create one solid sheet. The other is T-nuts and bolts.

Originally, I wanted to use ‘fanged’ elevator bolts, but they stick out at the bottom and may make the installation of water tanks more complicated. Therefore, I choose to use 18 T-nuts and bolts; about six for each plywood sheet. Certain locations were blocked by the fuel tank and I ended up using two less, but I feel assured that they will do their job. The dadoes on each plywood sheet enhance that.

The hardware is all stainless steel to minimize rust and is bought with different length bolts. I try to install then within the floor ribs, where the distance to the plywood is minimal, but was forced at some locations to place them outside the floor ribs. That added approx. half an inch to the length of the bolt.

I did not anticipate that the T-nuts would lie on top of the plywood, so I used a Forstner bit to create a shallow hole in the top of the plywood as wide as the width of the T-nut. That was done after the hole was drilled from below and before the hole was widened at the top ¼ inch to facilitate the T-nut.

With the T-nut solidly attached in the hole and to the plywood, it is easy to insert the bolt from the bottom. Afterwards, cut all bolts off with a hacksaw or oscillating tool and sand flush.

Stainless steel hardware can be quite expensive and you may save some by ordering on-line.

To add extra protection, use some undercoating to cover the bolt locations. Let it dry and give it a second coat. Shake the spray bottle well, before each use!

To minimize moisture penetration, I use a caulk to fill the ¼ inch gap between the plywood and the walls. I used Loctite PL-S40 polyurethane window, door & siding sealant, as the polyurethane may have a less corrosive impact on the steel than other caulks.

This is the final part in this series of articles about the installation of an insulated sub-floor. At a later stage the entrance area at the sliding door will be finished, when the finish flooring is installed. At that time, the finish flooring will also be extended a bit into the rear of the cabin. At the rear doors, a wooden threshold is planned at a later stage, that covers the plywood dado; it will extend a bit above the plywood, to account for flooring material.