Screed on timber boards

[gmd255]

I have to ask...

Im planning to make a 40 mm thick screed on timber boards (boards are approximately 50 mm thick but without tongue and groove joints).
There is no connections between screed and boards (no interface connectors).
Since there is nothing connecting boards together (no tongue and groove) Im wondering if screed can be helpfull in situation when we put a concentrated load on it - lets say large pot for flowers.

Putting high concentrated load on boards may not be a good idea since they are not connected/fastened together, which means the load is not spread over several boards. Because of that a singel board has to take the whole load itself.

Im wondering if screed is stiff enough so its effect can be similar as if timber boards were actually fastened together?
I hope yo understand and can advice me(English is not my 1st language).

 

[dik]

Can you use plywood? OSB? aspenite? and locally reinforce (sister) the floor joists or provide trimmers to distribute the load? Seems silly to add all that dead load.

Dik

 

[gmd255]

tnx for reply.
what are trimmers?

screed is there for other puposes, so it will be made anyway... but I was wondering can it help that way?
I cant use OSB/plywood since I have to use boards. I cant connect boards on top because i need a flat surface (hydro insolation on top of boards).

 

[dik]

Screed for drainage? You are adding another 20-25 psf for the concrete. By hydro insulation is this for electricity or water. Using added boards (2x6 T&G, maybe) you will not likely increase the strength appreciably unless you use an adhesive.

Dik

 

[gmd255]

Screed is placed there for preventing fire (fire engineer put it there) and protect hydro insulation. There is a terrace on top (coffee shop).

 

[jayrod12]

Shouldn't the fire protection be from the underside, since fire goes up.

Regardless, I wouldn't expect there to be significant load sharing from the concrete topping below, maybe 40mm in either direction from the edge of the point load edge (e.g. planter edge). But that's likely not enough load sharing for what you're after.

 

[dik]

OK... can the FRR be achieved by some other means?

Dik