ᐅ Insulated floor for garden shed with paving slabs?

Created on: 1 Nov 2023 12:02
J
Jansepp
J
Jansepp
1 Nov 2023 12:02
Hello,

We have a masonry garden shed built on a concrete foundation. We plan to install a solid fuel burner with a buffer tank inside. Accordingly, everything will be insulated. I would like to insulate the floor in a simple way and have considered the following approach:

1. Vapor barrier

2. 5 cm (2 inches) of screed-grade polystyrene insulation

3. 2 cm (0.8 inches) tongue-and-groove OSB boards on top

4. 5 cm (2 inches) of concrete paving slabs glued and grouted over that

With this 12 cm (5 inches) total build-up, I have evened out the previous step up at the door that was bothering me.

My idea was to avoid a concrete screed with tiles and instead solve it in one go using the concrete paving slabs.

It should be functional and cost-effective, with the premise that it can support the approximately 350 kg (770 lbs) wood gasifier and the 800-liter (210 gallons) buffer tank.

My main concern is the point load. The screed-grade polystyrene is foot traffic resistant and comes from our home renovation, where it was installed under the screed.

As mentioned, the heating unit and buffer tank are quite heavy.

Would you recommend a different insulation material instead of the screed polystyrene?

Which adhesive would you suggest for gluing the 60 x 30 x 5 cm (24 x 12 x 2 inches) paving slabs to the OSB boards?

How much expansion gap would you leave around the edges?

Thank you very much for your advice.
J
jens.knoedel
21 Dec 2023 13:14
Jansepp schrieb:

Would you choose a different insulation here instead of the screed Styrofoam?
Install a composite screed beneath the two heavy parts. Insulate the rest properly—no matter the setup (maybe PUR instead of Styrofoam). 5cm (2 inches) of Styrofoam provides very little insulation.
Instead of OSB/concrete boards, you could also use dry screed panels.
H
Harakiri
22 Dec 2023 16:09
I would recommend using boiler stands, which are available ready-made in various sizes. They come with integrated PU core insulation and a steel plate on top, approved specifically for such point load cases.