Newshound wrote:
Am I doing the right thing or is there another technique I could try?


Not worth worrying about blocking the holes, probably. Get yourself an angle
drill so that you can drill the holes square. There's a Ryobi kit with a
standard and an angle drill, plus a pair of 14.4 volt batteries and a big 1
hour charger for about £110 in Screwfix and elsewhere. Probably the best
tool I have bought in the last 20 years.

or an angle adaptor for a regular drill and drill out the existing holes
more in the direction you want them, and larger: 25mm is too tight for
22mm pipe, 32mm is more like it. Polypropylene pipe (e.g. Hep2O) is also
a lot easier to work with in 22mm than PEX (e.g Speedfit) as it's softer
and more flexible. You may also find it easier to join under-floor
joints with compression rather than push-fit since you can get the pipe
into the fitting with practically no pushing force and see that you've
got it home before tightening up the joint, whereas with pushfit you can
have a devil of a job pushing the pipe into the fitting if it's already
tight in the holes through the joists.