First post - back of house extension & reconfiguration

[JK1983]

Hi, as the title suggests this is my first post having stumbled across this forum - be gentle! 

 

We've been renovating our Victorian house for a couple of years and are planning a rear extension to maximise access to the garden. We'd like to incorporate the footprint of one one the existing downstairs rooms into the extension (creating and L-shaped space) , we would like to have the same floor finish through the entire space and would like polished concrete with under floor heating if possible.

 

My query is how feasible it will be to have a concrete floor in the existing section as the floor is over the cellar so may present structural issues as well as issues with levels. Does anyone have any knowledge or experience of how we might go about achieving this?

 

Cheers!

 

 

[Russell griffiths]

you will need to remove all the original floors to get adequate insulation in to make the ufh viable, do not believe any of the BS that the suppliers will tell you that 10mm insulation boards on top of a cold floor will be perfectly adequate for your ufh, it will obviously work but you will spend more money heating the ground than heat entering the room. 

 

Any reason for ufh ??

[ToughButterCup]

1 hour ago, JK1983 said:

...

so may present structural issues as well as issues with levels.

...

 

Welcome.

Ask a structural engineer (SE).

You're maybe new to this game (?), so a quick explanation might help

 

Network a bit in your area for local, respected SEs.

Make initial contact with all of them, describe the problem, and then ask them - if they're interested in the job - to submit a fee proposal. Don't let any professional over your threshold without a clear statement of their fees and Ts+Cs. You'll get a bill even if they do no further work for you.

 

Get three opinions.

And then ask a local builder for a tooth-sucking session - without telling them up front that you have an SEs opinion. In other words, arm yourself before talking to the builder. The SE might suggest a builder and vice versa.

You might tell that old wag @Russell griffiths that you want ufh because you want to keep warm......?

 

[JK1983]

No particular reason for ufh other than concrete is cold and it frees up wall space.

 

In removing the original floor I'm imagining I'm also going to need to remove the joists and introduce a suitable substrate at the right level to allow the concrete floor to be built up to the required level... Does this sound feasible?

[JK1983]

Cheers @ToughButterCup I work in the construction industry so understated the process and requirements but I don't work with houses, extensions etc so am trying to understand the feasibility of having a concrete floor over an existing cellar in a 160yr old house. 

 

I would like the same floor finish throughout, on the same level - I guess I'm trying to suss out if it's possible / cost prohibitive.

 

I'll make contact with some Structural Engineers and see what their thoughts are.

 

Cheers

[Mr Punter]

It would be a big job to replace the suspended timber floor with a suspended concrete floor.  Probably easiest with concrete beam and block but will need insulation, then your concrete topping.  Allow 150 depth for the beams, 100 for insulation and 75 --100 for the concrete topping.  The new bit of floor could be ground bearing if you are not on clay.