Pushfit V Compression?

[ABCwarrior]

After the umpteenth time our downstairs water supply has frozen I'm planning to replumb and surface mount everything above FFL.
It's a house on stilts in the Cairngorms, timber floor sections with poorly fitted draughty ply undersides, poorly insulated pipes (can anyone advise if it is building regs to use 15/25 Thermaflex within an unheated floor? Ours has 15/13 thrown loosely at it) and the pipes are within the floor...
Hopeless situation, and a cost cutting exercise with as disastrous results as them using cheap wire in the "Towering Inferno"....
So, given that everything is quite accessible above FL, I'm planing to cut into the Hot where it comes down from above and branch it to the shower/sink/kitchen sink. At present the 25mm Cold supply pipe rises into the cavity behind the cistern then branches off to supply upstairs and disappears the other way below the floor. I'll cut it here and branch it out too, including the toilet. All pipes where contained in walls above the floor will be immaculately insulated and the cavity filled with insulation to boot. to stop draughts. Ideallly I want to surface mount them and keep out of the walls. The toilet sink will need this anyway not putting anythng in external walls.
So, after a long winded intro can anyone advise should I use compression or pushfit connections? I'm not a plumber(stonemason JOAT) but have done my own showers ok before, but I'd rather use pushfit this time to speed things up and keep it simple- if so which brand is superior?
I'm pushing to get the builder/seller/architect to bear this cost but they are useless and they will drag their heels rather than admit they have cocked up. They tried boxng the area off in the summer but I knew it wouldn't work the draughts are everywhere supercooling the pipes.
The builder is NHBC registered does this mean I could claim off them regardless? The workmanship is poor as is the design!!

 

[bengasman]

I'd think twice before doing this yourself. You will more than likely void any warrantees you had, and on top of that it is unlikely to solve your problem.

 

[electronicsuk]

If it's solely a choice between push fit or compression then push fit has to win. Personally, I hate compression fittings, and will avoid them wherever possible. It's probably just the way I work (what with not being a plumber), but I find that at least one in every ten joints has a small weep and requires further adjustment. I've never had this with push fit.

What I do prefer, however, is soldered connections. I've never had one of these fail so far, and it's a tried and tested method that is practically guaranteed to last for tens of years. The O rings inside a speedfit fitting will have failed long before a good end feed or solder ring fitting gives you any trouble.

 

[ABCwarrior]

"it is unlikely to solve your problem"

Eh? Given that before and after they tried boxing off the underside of the house our upstairs supply has been perfectly ok I know for sure that disconnecting any pipework that disappears into the floor and keeping it above floor level will definitely work.
The floor sections are 300mm deep and the pipes are 100mm from the BOTTOM. Yee ha!!
Thanks for the response electricsuk think I will use HEP20. If I do it myself I will know it's done right. The plumber we had came round to replace 2 blown braided pipes to the HW in the upstairs and downstairs toilet sinks, to do this he needed to disconnect the linkage for the plug. Didn't even tighten these back up.