Insulate floor in conservatory

[tumboerik]

I want to insulate the floor in the conservatory. Today, there are only stone slabs.

I'm thinking of laying a wooden framework with foam in the "compartments." It feels like the cheapest option.

But how exactly would you have done it?

 

[Jonatan79]

What's under the slabs?

 

[tumboerik]

What is under the tiles?

Sand/grus

 

[Jonatan79]

What kind of flooring do you want afterwards? Maybe styrofoam plus surface/finish/floor would be enough?

 

[tumboerik]

I have been considering wall-to-wall carpet, alternatively parquet flooring.

I think the floor would become very uneven if I laid the floor directly on styrofoam, unfortunately.

 

[tumboerik]

Bump

 

[anfr018]

Facing the same dilemma, tiles on sand and considering using styrofoam as floor insulation. Curious about how it turned out??

 

[tumboerik]

Hi! I'm actually working on the floor right now!

I laid pressure-treated beams directly on the slabs. I used wedges and blocks where needed.
Then I placed insulation between the beams - the kind of insulation used in the ground.

Then I screwed on decking.

 

[tumboerik]

I have also insulated the interior walls and nailed raw boards (end groove).

I took the opportunity to run new cables for wall outlets as well before nailing the boards.

 

[Jonatan79]

I wouldn't have applied pressure, unnecessary. What happens if they become damp and start to stink?

 

[tumboerik]

I wasn't entirely sure that treated wood was necessary, planned to use regular joists. But just before I started the construction, the downpours came in late summer and when I saw how damp the slabs got, I decided on treated wood.

I've never heard of the wood starting to stink?

Good thing I have plenty of ventilation then 🫡

 

[Jonatan79]

Where does the moisture come from? Do you have good drainage around the house?

 

[tumboerik]

The moisture comes from the ground beneath the tiles. However, there was a monsoon-like amount of rain during the period when I noticed the tiles becoming damp.

Well, I don't think the drainage around the sunroom is optimal. It's just a kind of concrete base around the whole room where the walls are built, I believe. Then it's filled with sand inside the base. It wasn't originally built to have a floor.

That's why I quickly abandoned the idea of parquet/carpet.

 

[Pappa1986]

But then the insulation will get wet in the future if the tiles got wet this past summer.

 

[Hjogvik]

If there is any risk that the floor might become damp from below, you should not use pressure-treated timber in the joist structure. This is a known problem with houses from the 80s when uninsulated slab-on-grade was used with pressure-treated beams that become damp, moldy with a toxic and strong smell. After an hour, it causes a headache.