I need to install a wooden floor in a tall garage that I have to give me some more room.
The span that the joists must cross is 3.5m, but what size joists must I use and how much room between them?

Thanx for any help in advance.

Dave

 

Don't know if this will help.
I don't know the answer to your question.
However, whenever I want to find answers to DIY problems I do this
Go into the largest builders centre which the trade use.
'spot' a friendly looking person of the correct trade and ask him/her.
Works every time!!
Probably best to approach 2 in a case like yours just to rule out the possibility of getting a cowboy.
None of our houses have ever fallen down, adn we've done a lot to them.
Self build is next!
Otherwisw there are some good books/sites about
Also the place where you are buying your joists from will probably have ex tradesmen who would tell you
Good luck

 

Dave,

All house floor-joists are generally spaced at 400mm centres ( 16 inches in Victorian measurements).
Also, an 8" x 2" standard timder joist is generally good for a 12 foot span, which is 3.66m.
So not far off. Will check with my builder butties tomorrow.
Pete

 

As PHD said - fairly standard spacing at 16 inch centres. 8 by 2 should be OK for a 12 foot span. Phone B&Q and Homebase. They should give you fairly standard answers

 

B&Q and Homebase are staffed by smelly muppets who are paid peanuts to know peanuts.

 

And I put so much time and effort into this reply...it was my first serious post, now you lads have upstaged me

 

Oh poor Scoobabe !!!
Never mind.

I found the DIY Doctor online. Ask him any question and he will get back to you within 48 hours.

He said 175mm x 38mm at 450mm spacing.

So there you go problem solved.

Thanks anyway for those who posted.

 

so that'll be 8 by 2 at 18 inch centres. I know about B&Q and Homebase, but the will look it up in a book that regulates building control for you. They do in Belfast anyway

 

I challenge you to find a straight piece of wood in either Homebase or B&Q!!

You are much better going to a proper builders merchants where you will get much better quality materials for half the cost.