How to raise floor?

[Backyarder]

An old laundry has been converted to a bedroom but the concrete floor level is not much above outdoor grass level and in heavy rain water has entered the room and rotted the bottom of the wall frame . I'm going to work on lowering the outside level to help water flow away from the room.

What I really want to do is lift the bottom of the walls and maybe concrete 100mm on top of the existing concrete floor. The room is approximately 3mx2m. How do I concrete a new floor then have the existing walls shortened at the bottom to sit on the new floor ?

[EricL]

Hello @Backyarder 

Welcome to the Bunnings Workshop community. It's sensational to have you join us, and thanks for sharing your question about how to raise your floor. 

In order to raise your walls, the entire room would have to be taken apart a new concrete floor base laid out and the room re-assembled. It might be possible to take your interior walls apart but raising it will affect anything that's attached to it along with anything above it. It's not something that can be removed by itself and modified to fit new conditions.

The wall frame and wall covering can be replaced and repaired, but that's about the extent of the modification you can apply to it. As an alternative, I propose installing a concrete plinth to the entrance of the room and running a drain channel in front of the laundry door. This will be your protection against flooding.

Let me call on our experienced members @Dave-1 and @Nailbag for their recommendations.

If you have any other questions we can help with, please let us know.

Eric

[Dave-1]

Evening @Backyarder 

Now thats a job and a half Not sure if its doable tho.

The height of a room should not be under 2.4m floor to ceilings.

I cant think of an easy way to jack up a room so the concrete can fit under the framework either. 

My solution would be along the same lines as yourself and @EricL and that is to install some drainage and the level of it is well and trully below your floor level.

Fixing the existing damaged walls if you go that route. Do you have some photos of the rotted sections? There are a few projects and questions amongst these pages where people have replaced the bottom rail in stages as they work their way across the wall. First step tho is to get that drainage sorted.

Dave

[Backyarder]

Thanks for the reply, I did say raise the walls but I meant shorten the bottoms of the wall frames are they are rotted from repeatedly getting wet. I thought I could cut the frames by 100mm, replace the bottom rail then lay a concrete slab 100mm thick while the walls were suspended, jacked up in place,  chocked, call it what you will. Once the slab is set , the wall would be sitting  on it. Just throwing ideas around. I'll definitely be sorting the drainage outside, which might give enough clearance to just replace the rotted framing.

[Backyarder]

I did say raise the walls , I meant shorten the wall by cutting 100mm off the bottom. Some how hold in in place until a 100mm concrete slab could be poured underneath. Maybe I watch too many restoration shows on TV.

[JacobZ]

Hi @Backyarder,

In theory, what you are proposing is possible, however, I wouldn't recommend it as a D.I.Y. solution as the risks involved are too great.

If you wanted to do something like this, I would suggest engaging the services of a suitably licenced builder for their assistance.

They will be able to assess whether the wall is load-bearing or not and with that information decide on the best method of supporting the wall and ceiling while the studs are cut, the bottom plate is reinstated, and concrete is poured underneath the shortened wall.

Let me know if you have any further questions.

Jacob