levelling garage floor

[hexdex]

Hi.

I'm converting my small garage into a music studio. My first job is to install some floor insulation, so my intention was to build a timber frame lay down some dpf and 50 mm insulation followed by 22mm t&g. Problem is that the otherwise sound concrete slab is very uneven, dropping about 50mm over 3 mtrs or so. What would be the best DIY method for levelling? Can I do it with the timber as I go, or am I looking at laying a new concrete slab over the existing one do you think.

Thanks.

 

[roryfirth]

I am doing something similar but have a drop of 160mm to play with.

I am fixing timber to the walls using 130mm thunderbolts every 2 bricks and then joist hangers off the timber to support the joists, using 45x95mm timber for both. These will be at 400mm gaps with 100mm celotex boards fixed inbetween. (this was the required thickness for building control)

Then i'm laying 18mm ply, heat matt, 5mm insulation and a laminate floor.

This will leave 30mm air gap underneath which the council have said they're happy with.

I'm also spraying a layer of bitumen paint on the floor before I do anything.

I looked into doing a screed layer but for the amount I would need it would be expensive and I couldn't find anyone who would do a concrete pour of 12.5sqm at 30mm deep.

Hope this helps.

Rory

 

[hexdex]

Thanks for the reply Rory. Your solution sounds like a good plan. The problem I have is that the drop I have is so uneven and runs from top right to bottom left, and to suspend the floor enough would mean I run out of height. All I can think of is to use assorted timber and packing as I go! Very time consuming, but all I can think of.