Door/hatch clearances and hinges

[Giblets46]

hi all,
Putting in a hatch to my man cave in the garage loft that opens on hinges to one side, looking to make the hatch more like a door than a simple flap and as such wondering how much clearance is suggested.
The frame for the hatch is 1000mm by 750mm (with the hinges down the long side).
The door is going to be 95mm thick (there is a lip and this makes it fit level with the floor). So the simple question is how much clearance should I leave along the edge (Read something like 5mm for a normal thickness door but the thickness of the door would increase this I would think, so maybe make it 740mm wide?!

Also because the floor (around the frame is 20mm thick chipboard, and am looking at the hinge opening at floor height, any suggestions on hinges? (Normal door hinges would have the screws passing too close to the chipboard), would back flap hinges suffice?!
Thanks

 

[foxhole]

Is the hatch to open up into room or hang down? Simple "T" hinge may suffice.

 

[Giblets46]

Door will open up into the room, room around the hatch will be carpeted.

 

[big-all]

i would make it from several 6x1"[143x21mm] or 7x1"[168x21mm] planed planks battonned together with a seperate lower trap door for the ceiling but beware it will be heavy

 

[Giblets46]

Cheers, it the frame around the hatch that's the issue for the hinge rather than the hatch door itself (will be using offcuts of 3X2 to make a frame, sandwiched between two 10mm boards).

 

[big-all]

the trouble you have if its 100mm thick and 750 wide the diagonal the leading edge will be around 10mm with the throw off the hinge taken into account
what is supporting the door in the shut position ??
if its a door stop it will have to be at least 15mm wide to support the door

 

[Giblets46]

Thanks, that's the figure I was looking for, not great! May have to consider the alternate edge which will benefit from other parts of the design (designed to rest against angled stairs ).
Edit: just measured door stop, a healthy 20mm. The chipboard flooring is not cut too neatly and sits about 5mm off the edge.

 

[big-all]

you realize my design will be quite heavy and yours is 2-3 times heavier than my chunky design
not a problem when the hinges take all the weight but pulling up over an open floor unless your sure footed and fairly strong i would try and lighten it

 

[Giblets46]

Cheers, just uploaded a picture of the frame, was hoping to install. Gas strut to help with the weight

 

[big-all]

is this at the top off a ladder or a stairs around 45% angle ??
aahh see the picture now 45-50% fixed in position but moveable only the 50-55% hinged to open normally

 

[Giblets46]

you realize my design will be quite heavy and yours is 2-3 times heavier than my chunky design
not a problem when the hinges take all the weight but pulling up over an open floor unless your sure footed and fairly strong i would try and lighten it

After sleeping on it think I'll get some thinner wood, should be easy to drop the weight by half (my intention was to use the off cuts originall)

 

[foxhole]

Weighted pully system would help counteract weight problem.

 

[big-all]

another point
if you have it backed or covered by carpet you will be limited to how it will open before rucking or folding the carpet stops it raising further along with hinge bound on the surface where it jambs on the carpet
you then take the 100 or so mm from the the total 750mm leaves you with 650mm opening??

 

[Giblets46]

another point
if you have it backed or covered by carpet you will be limited to how it will open before rucking or folding the carpet stops it raising further along with hinge bound on the surface where it jambs on the carpet
you then take the 100 or so mm from the the total 750mm leaves you with 650mm opening??

Seems some confusion here.
Carpet will cut to size and placed over the hatch, so shouldn't cause an issue.

Bit confused by the taking 100mm from the total part?!

 

[big-all]

just pointing out another reason for slimming down the thickness
you door can only fold back flat if the pivot point or knuckle is proud off the surface off the carpet so a possible trip hazard as will any structure attached to help lifting it