Decks, Patios, Porches and Docks - Insulating a concrete floor

I am converting a back porch into a 3 season, all window, room. My concern is the concrete floor. I would like to insulate it somehow before installing carpet.

Got any ideas?

Oh yes, Stepping out of the house there is a 6" drop to the concrete. The windows will set in a 3/4" hi track around the room.

Bill Phelps,

Normally, 2x W/T sleepers are installed with rigid insulation placed between them. In your case, you have windows that are 3/4" from the concrete which makes for an unsightly appearance from the outside but, you could always paint your rim. Then place 3/4" ply above, pad and carpet.

My other concern would be glass replacement if necessary and how you would be able to remove in case of breakage. Consider your choices and application used.

Hope this helps!

Doug,

I think maybe I did not explain myself well here. Pretty much of the industry standard, the bottom channel, is approx 3/4" tall.

An idea was to lay plastic down on the concrete first, tounge and grove plywood then whatever flooring.

Is plywood a choice in this application?

Thanks!

Bill,

3/4 T & G plywood is the normal subfloor but the issue of anchoring the plywood to the concrete floor. You can lay plastic down but installing the 3/4 via ramset or mechanical anchors will create a problem that I would not want you to deal with...moisture...wicking up into the plywood. Even then, W/T plywood is expensive. You may want to apply a sealer to the floor prior to your suggested application to minimize this.

The other issue is what happened to insulating the floor? You didn't mention about this or are you foregoing that idea?

My previous post would be the best way, especially the insulating. IF window replacement was viable it could solve the appearance questions but I realize the expense. Besides, if you could do it that way, it would only take a heat duct to convert this to habitable space.

Hope this helps.

3/8 r foil insulation with 1/2 x rated plywood. The r foil acts as a moisture barrier. Then carpet over that. May work? The r foil may work better placed on top of the plywood rather than underneath, id expirement with that. or build a knee wall and install shorter windows? -Josh

Thanks for your reply!

The enclosure is now being built and I will begin on the floor in a week or two.

Thanks again!

If this room is being built on an existing concrete patio slab, that slab should be sloped away from the house. To compensate for that slope, whoever is building the room will use wall panels for a filler under the transom windows, and those fillers will be cut at a slight angle to keep the transom windows level as they get farther away from the house. You will have more than just the 3/4" of extruded floor track from the slab to the bottom of those windows, so working some sort of insulation should be easier. As far as being able to replace window panes, as Doug pointed out, that really shouldn't be much of an issue. In adition to the 3/4" floor track, you will probably have another inch or so of window frame below the actual pane of glass. And, if these are the types of windows I think they are, the panes would be replaced by removing the spline from the OUTSIDE of the window frame, and the new pane would be installed from the outside.