Copper, carbon steel, stainless and press fit pipework, fabricated on site, installed, supported, insulated and pressure tested. The part of a mechanical installation that everything else depends on.

Brazed and press fit copper for water services and smaller heating distribution, with press fit used where a live building cannot take hot works.
Welded and grooved carbon steel for heating, chilled water and larger distribution, fabricated to suit the route rather than forced to fit a standard spool.
Stainless distribution and process pipework where the medium, the hygiene requirement or the environment calls for it.
Correct bracketing and expansion provision, insulation to specification and clear identification and flow direction throughout.
Both, depending on what suits the job. Repeated spools and anything that can be measured accurately from the model are better fabricated off site. Plant room headers and anything that has to fit around a building that is not quite what the drawings said are almost always better made on site.
Where it is unavoidable, yes, under a hot works permit with the fire alarm isolation, extinguishers, fire watch and post work checks agreed with the building manager beforehand. In most occupied buildings, though, the sensible answer is to design the hot works out and use press fit or grooved systems instead.
Every time, before insulation and before anything is concealed. Test pressures and durations are recorded and issued. Testing after the ceiling grid is in is not testing, it is hoping.
We can carry insulation as part of the package or work alongside a specialist insulation contractor if the client already has one. Either way the sequencing matters: pipework tested and signed off before it disappears under insulation.
Yes, and the first step is establishing what is actually there rather than what the old drawings claim. Once the existing material, size and condition are confirmed, tying in cleanly is straightforward. Where the existing is at the end of its life we will tell you, because a new branch off failing pipework buys very little.
Based in Dublin and working across the city and the surrounding counties most weeks, so getting out to look at a building is rarely more than a few days away. Work further into Leinster is no problem for the right project.