DIY drop down loft hatch

dannyjebb

We have a loft hatch that is larger than average and we don't want to make it smaller as we keep a push trolley up there. It is currently approx 775mm x 750mm
I am thinking about making a drop down loft hatch that will simply be a piece of ply, painted white to match in with the ceiling, 2 x touch latches, and some hinges. A few pieces of architrave to finish it off around the edges and a piece of PIR insulation on top of the ply for insulation finally some strips around the ply board to add a bit of extra draught exclusion. 
Other than this I can't think of anything else that is needed?
I have looked online and a company called Jupiter blue will make a custom fit one but its £150, From the bits above the cost would be about,
plywood - £14 (for a piece that is far more than needed
touch latches x 2 - £4
hinges x 2 - £4
Architrave - £6
PIR  £5
Draught strips £4
Total - £40

Is there anything obvious I have missed?

Thanks

Danny

Murmansk

My observation would be  to say that even though you measure the hatch hole carefully and get a bit of plywood cut to the appropriate size, you might find that the hatch is not properly square, so the plywood will need adjusting because it binds once you have fitted the hinges.

dannyjebb

Murmansk said:

My observation would be  to say that even though you measure the hatch hole carefully and get a bit of plywood cut to the appropriate size, you might find that the hatch is not properly square, so the plywood will need adjusting because it binds once you have fitted the hinges.

Hi Thanks for your reply.

Fortunately, we have cut out the hole ourselves and hopefully, it is square  

Ectophile

Murmansk said:

My observation would be  to say that even though you measure the hatch hole carefully and get a bit of plywood cut to the appropriate size, you might find that the hatch is not properly square, so the plywood will need adjusting because it binds once you have fitted the hinges.

Been there.  I bought a kit of parts to convert my push up board of a loft hatch to a drop-down one.  It should have been simple.

By the time I had finished, I had built a completely new hatch from scratch, because the old one was so far off true that it just wouldn't work.

Jonesya

Are your hinges going to be screwing into the face of the plywood or into the end of the plywood, where the fixings won't be as secure? You might need to fix some additional timber to the ply, to fix the hinges into.