Has anyone done this

[Oldman]

Take two hollow core doors and glue them together fill with insulation and use them for the floor.

[boomboomtulum]

Cant say that I have. Just remember that Hollow cores are just that hollow. Generally 1x pine frame with a luan or masanite skin 1/8 thick. While they are built rigid for doors you can still put your fist through them. Not much compressive strength. For the trouble of removing the skins, insulating glueing up, 1/2 ply would still give you some r-value or as some have done insulate under the floor.
Just a thought though.

Dave

[Jiminsav]

I think Roly did that on the ¼ Nelson. it may have been only 1 door though.

[tinksdad]

I think Roly did that on the ¼ Nelson. it may have been only 1 door though.

I'm sure he will pipe in in due time, but Roly did use that on the 1/4 Nelson. That's where I got the inspiration to start my build from. I was tempted to go the hollow core door route, but decided to fabricate my own when I get started. I am going to use 1 x's (either 2" or 3") for the outer frame and center supports and skin both sides with 1/4 ply. Foam sheets for insulation before I add the second skin. The cost will be a little more than an HCD, but I end up with the exact size I need , rather than scab some extra pieces to the edge. 1/4 or luan underlayment should be fine.... I don't plan on dancing on it. Putting a TD together isn't a whole lot different than the way most urban transit buses are built, just on a much smaller scale. I worked in a body shop for public transit for a number of years and had more than one torn down for total rebuild. How else do they get two million miles or more before they are replaced?

[Airspeed]

Most hollow core doors Ive seen have a matrix of cardboard inside to keep the panels flat, I dont know how much of a pain it would be to tear out the cardboard and replace it with insulation. I used one as a table in my shop, when I dropped a quart of paint on it the can went right through the first layer. I would hate to see what would happen if you put your knee on it. Aaron

[bobhenry]

I just finished the floor for my 3rd tear and I used a 2x4 rim and a top and bottom layer of 1/2 " osb . I ripped the 2x4 to 1 1/2 x 3" actual size and filled the cavity with 4 layers of 3/4 " ridgid foam board insulation. Took just over an hour to build the entire floor. The most time consuming was glueing and screwing the perimeter every 8" My floor was 4x8 so no laps were needed but if you are oversized just add a 2x3 where needed to catch the lap joint.