Joists in suspended floor of new conservatory

[BigBadJay]

I'm currently building a conservatory (internal measurements are 4.5m wide x 3.75 projection) which will need a suspended floor due to outside ground level being lower.
I have opted for timber joists which will rest on the inner skin of the cavity wall at the projection end and off joist hangers bolted to the house wall.

Similar to example 4 on this page :-

http://www.conservatory-base.co.uk/concrete_bases.htm


Will 150mm x 50mm at 400 centres suffice for this span?

 

[Static]

No

You'll be looking at 47x195 joists at 400 centres

 

[BigBadJay]

Cheers Static...much appreciated

hmmm, I was thinking of putting laminate flooring down on top of damp resistant plywood.

What depth should I allow for laminate+underlay+plywood+joist?

Cheers

 

[splinter]

The depth I would recomend is:- the thickness of the laminate that you will be buying +thickness of under-lay +thickness of ply+width of floor joist

 

[BigBadJay]

Thanks for that

I really meant, is there a required ply thickness or will any do (i.e. 19mm dampresistant chipboard)?

What is the average underlay and laminate thickness?


Also, would there be a problem suspending the joists from hangers on both walls are am I better resting one end on the internal wall?

Thanks

 

[splinter]

!8mm ply
2mm underlay
14mm engineered wood flooring and I cannot see a problem with joist hangers at each end

 

[BigBadJay]

Cheers splinter

Gonna get some Multi truss hangers and use coach bolts to fix to the masonary....should be solid enough

 

[joe-90]

You are better off with masonary 'anchors'. Those things that open up when tightened. Coach bolts will only grip in plastic plugs and you can't tighten them very tight.

joe

 

[BigBadJay]

Will do, thanks joe

 

[Mick Leek]

BigBadJay

Get excaliber bolts...

newish product.

Stronger than Rawl bolts. All you do is drill the correct size hole and screw them in... No need for plugs and you can remove them and reuse should you cock anything up... Not that you will..

I used them for the wall plates on my new extension and they are supporting a few tonnes of wood and roof tiles.

Mick

 

[BigBadJay]

I've already ordered some shield anchor bolts but thanks for the suggestion mick.