Thread: Bathroom floor construction in 1930's house

help me please someone. i've ripped out the bath tub in a californian bungalow type house in inner west sydney to discover that underneath is a concrete floor. i cant get underneat the bathroom floor because the bathroom area under the house is all bricked in. a plumber tells me that in the old days they would fill the sub floor space with ash and them pour the concrete floor. my question is..what is holding the concrete floor? if its just the ash fill the ash would compact over time so the slab might drop with it. is there any type of pier along the walls to support they weight of the slab? there is a small opening in the floor for the drainage pipe but i cant make out if its reinforced with steel either.

i want to level the floor and put porcelain tiles on it. this would add more weight to the flooring (an extra 80kg over 2.3sqm area) . also want to put in frameless (extra 80kg). also want to put vanity unit (extra 50kg). in addition to the live load (say max 190kg)....is the floor going to hold? will it crack in half while were brushing out teeth and fall into a pit of creepy crawlys?

the bathroom is 1.5wide by 2.3 long

I have recently bought a house of similar era and location but I have access under the house. The bathroom floor is a poured concrete slab over sheets of corrugated iron with engaged brick piers supporting the the iron sheets along with a couple of timber props that only helped while the slab cured. They have since been removed as they were no longer supporting the weight and were perfect termite food. The concrete slab has steel bars and reo running through it same as they do these days.

I have ventured under a few houses of this age and they all seem to be of similar construction. The area that mostly has building rubble with a slab poured over the top is the front porch for some reason.

My unlicensed opinion would be the extra weight of some new tiles etc would not cause the floor to cave in.

hi drawkcab, thanks heaps for you input. your unlicensed opinion may be just what i need.

of the ones you've seen you recon any of them would use timber joists as the structural support for the concrete flooring? thing is the subfloor of my bathroom is bricked in but i can see timber floor joists running into the subfloor but unless i knock a whole in the subfloor wall (with some risk) i have no way of knowing if the timber bearers extend the lenght of the bathroom. i can see though that the timber joists are not running flush against the brick wall but are a bit over 1/2 brick with from the wall so that could suggest that there are brick piers used.

if the timber joists extend the length of the bathroom then it would like smack in the middle of where i plan to put the toilet pipe.

I would advise that 99% of these old floors will be good for another 100 years.

If you really want to test it just drag the old bath back in and fill it along with as many drums you can fit all filled with water.

I'll give you 5 to 1 on no problems.

PS. they don't build em like they used to.