replace suspended timber floors with concrete floors, or not?

Linto

Hi guys,
We're totally renovating a house we've just bought. Will be our family home for many years to come hopefully :-)
I've just had a conversation with the QS on the job who is really pushing me to replace current suspended timber floors with concrete floors. It will cost ~€5k. I'm just not sure its worth that??
We have an extension going in at front and rear with new concrete floors in these. Currently the existing floor has zero insulation.
Any advice? Money well spent or not really??

A fella called fish

What does the Project Architect think?

Linto

A fella called fish wrote: »

What does the Project Architect think?

"A nice to have"

sinnerboy

Technical considerations

Raised timber floors must be ventilated so if the front and rear extensions block off the ventilation openings you must ensure that ventilation ducts are built into the front and rear floor construction to provide an airpath to the "trapped" timber floor.

If built correctly a raised timber floor is built "2 steps up" from the footpath level - again to ensure there is a spacious enough void under the floor boards for ventilation. Concrete floors built economically need only be built "1 step up" . So if you are keeping your floor level constant the new concrete floors will require extra fill to bring the floor level up . By extra fill I mean more fill than would be required if you did not have to raise up to the existing timber floor level.

Whatever else you do at a bare minimum lift those floorboards and insulate the floor - do not leave it uninsulated . You would regret that bitterly every time you walked barefoot on the floor in winter.

Architectural considerations

If you take the existing timber floor out and replace with concrete ( insulated of course ) then you can set the floor down by about 150mm , maybe more. The increase in floor to ceiling heights is not just a nice to have it is a massive architectural improvement. The entire ground floor level will feel a lot nicer.

If you are tempted by this some items to bear in mind

a) your stairway will require 1 more step at the bottom
b) all doors will have to be replaced
c) window cills may need to be lowered.
d)skirting boards have to be replaced and a 150mm strip of internal plaster above will be required.

If you can stretch to all of that you will give the house a massive "wow factor" boost.

psychhead

We are currently renovating also and just replaced out timber suspended floors with concrete and kingspan. Did it ourselves, reckon it cost no more than €1500. If your willing to do a lot of the labour yourself its easily done, the levelling of the concrete however is best left to someone experienced. We were lucky and called in a favour from family.

Linto

Are we always prone to rodents with the suspended floor? Any info on this aspect of the old suspended floors?

sinnerboy

It does happen. As winter approaches you find that small creatures will seek shelter wherever they can.

builder007

Can this actually be done? If yes would anyone please outline the steps? I'm considering doing this in the n X couple of months.

Johnrlalor

We are considering doing this ourselves, does anyone have any ideas on cost or other issues we should consider?

enricoh

Johnrlalor wrote: »

We are considering doing this ourselves, does anyone have any ideas on cost or other issues we should consider?

Just doing it here at the mo at front of house , if yer handy at all it can be done cheap enough.
Disconnect the rads, cut out the timber. Dunno if u have radon in your area
The ground underneath was decent so took top inch off n wacked it, build up with 804 n wack it, screed of sand on top. Plastic on top, 4 inch insulation and 4-5 inch concrete.
Just getting a fella monday to throw in concrete n level, myself and a friend did the rest.
Bloody concrete n insulation got a fair jump in the last year though!

Keedowah

enricoh wrote: »

Just doing it here at the mo at front of house , if yer handy at all it can be done cheap enough.
Disconnect the rads, cut out the timber. Dunno if u have radon in your area
The ground underneath was decent so took top inch off n wacked it, build up with 804 n wack it, screed of sand on top. Plastic on top, 4 inch insulation and 4-5 inch concrete.
Just getting a fella monday to throw in concrete n level, myself and a friend did the rest.
Bloody concrete n insulation got a fair jump in the last year though!

Did the same thing myself last year - did all the work ourselves and did the plumbing at the same time. Instead of going with concrete on top we went for a liquid screed floor and it worked out great. You need to get your levels right though for before they come in to pour the screed.

fmlarnapairce

Did ye consider installing ufh while taking up suspended floors?

Keedowah

fmlarnapairce wrote: »

Did ye consider installing ufh while taking up suspended floors?

We didn't.

Wildly Boaring

enricoh wrote: »

Just doing it here at the mo at front of house , if yer handy at all it can be done cheap enough.
Disconnect the rads, cut out the timber. Dunno if u have radon in your area
The ground underneath was decent so took top inch off n wacked it, build up with 804 n wack it, screed of sand on top. Plastic on top, 4 inch insulation and 4-5 inch concrete.
Just getting a fella monday to throw in concrete n level, myself and a friend did the rest.
Bloody concrete n insulation got a fair jump in the last year though!

Make sure any stone under a floor is T1, T2 and/or T3. Most quarries test all cl804 as T1. Seen some still not. T1, T2 and T3 tested for pyrite. Again T3 in lieu sand.


I'd be wary of just throwing plastic down without spec and junction design for moisture too. Or just ignoring radon altogether.

Least it'll be cheap

Pkiernan

Linto wrote: »

Hi guys,
We're totally renovating a house we've just bought. Will be our family home for many years to come hopefully :-)
I've just had a conversation with the QS on the job who is really pushing me to replace current suspended timber floors with concrete floors. It will cost ~€5k. I'm just not sure its worth that??
We have an extension going in at front and rear with new concrete floors in these. Currently the existing floor has zero insulation.
Any advice? Money well spent or not really??

I would definitely go for a regs compliant insulated concrete floor.
The comfort factor alone is worth the money.