Fitting a Door

I bought a new door and jambs

anyway fitting the door jambs is never easy
once the opening was cut in the head and the sides nailed i slid the whole frame in and began nailing using 50mm brads just to hold in place

I checked the level with spirit level up the sides of frame and was almost spot on

so then once door was hinged it swings no worries.

I also nailed some 65mm bullet nails into thicker side of frame

the next day the door wouldn't close and there was no gap bottom side where door closes.
I then nailed this side in my and levered out hinge side 1mm or so and door is shutting ok

This happened overnight
would it be due to the fact that I haven't fixed archtraves or is this normal with timber swelling.

Will it fix this problem of gap creeping when architraves are fitted

More likely that you didn't use packers on the hinged side of the jamb. Brads will bend if the distance between jamb and frame is too great. Make some 2,3 and 5mm MDF packers. Use a chisel to even out the gaps again.

If I picture this correctly, the bottom of the hinged side of the jamb has simply slid along the 65mm bullet head nail toward the frame.

When you fix the architrave this will obviously help, but I never rely on this to hold the jamb in place.