Garage conversion raising floor height

[Notch7]

I use the NHBC span table.

http://nhbccampaigns.co.uk/landingpages/techzone/previous_versions/2010/Part6/section4/appendix.htm

A 170 x 47 gives a 3.7m span - going to 8 x 2 wouldnt be a bad ides.

 

[Al@n]

Sorry, I meant to say 'If you are spanning 3.7m use 200 x 50mm tanalised softwood joists at 400mm centres '.
170 x 45 might be ok, Notch 7 will have to confirm that, I know 200 x 50mm at 400 crs

will span up to 4m ok.​

yes ,I understand that but garage floors are usually near ground level which implies your finished ground floor level is about 610mm above ground level - is that the case ?
yes you will need insulation, but what are you converting the garage to ? Building Control will need to approve the insulation specification as well as other things.

Yep that's correct the finished ground floor level is 610mm

I'll be converting the garage into a habitable room, could i insulate the floor with mineral wool, will also double check with BC if this is acceptable

If I'm not mistaken only the external facing walls need insulating? And the internal walls i could dot and tab with just plasterboard?

 

[Al@n]

I use the NHBC span table.

http://nhbccampaigns.co.uk/landingpages/techzone/previous_versions/2010/Part6/section4/appendix.htm

A 170 x 47 gives a 3.7m span - going to 8 x 2 wouldnt be a bad ides.

I'll go with 8 x 2 with 400mm centres?

how can i calculate how much I'll need based on the length and width of the garage or is that the link you posted i need to look at?

Is the preferred method two screw or nail them?

Securing the wall plate to the wall, what fixings would you recommend?

 

[^woody^]

Excellent thanks, so is tanalised timber the same as kiln dried, and treated timber or are they 3 different types? or perhaps more

"Tanalising" is a treatment process for damp and insect protection. It is not kiln dried, which is wood that is just dried but not treated.

 

[Leofric]

I use the NHBC span table.

I looked back at my Part A load tables and 170 x 47 are on the limit or even overspanned depending on which part you read off, anyway 200 x 50 has been decided so that is ok.

I'll be converting the garage into a habitable room, could i insulate the floor with mineral wool, will also double check with BC if this is acceptable
If I'm not mistaken only the external facing walls need insulating? And the internal walls i could dot and tab with just plasterboard?

I know it has been said before on here but you can't really expect to go to Building Control with queries at every step of the way,they are not there to provide a technical design service. You should really plan out the design and know the construction specification before you start building.
ps you must have quite a few steps up to the front door - you won't be having a disabled access
good luck with it anyway.

 

[Notch7]

I'll go with 8 x 2 with 400mm centres?

how can i calculate how much I'll need based on the length and width of the garage or is that the link you posted i need to look at?

Is the preferred method two screw or nail them?

Securing the wall plate to the wall, what fixings would you recommend?

Rawlbolts I should think.

Always nail joist hangers, nails have much higher shear strength.
30mmx 3.75 twist nails.

 

[Al@n]

Rawlbolts I should think.

Always nail joist hangers, nails have much higher shear strength.
30mmx 3.75 twist nails.

Many thanks notch for the info its been invaluable!

 

[big-all]

as an aside
you may have a slope on the garage floor so use a level rather than measuring from the floor up

 

[Al@n]

as an aside
you may have a slope on the garage floor so use a level rather than measuring from the floor up

Will use a laser level