Isolation valves on central heating

[reynard883]

I am currently building an extension. As we are just finishing one room at a time I had an idea of using isolation valves below the floorboards for each drop to the proposed radiators.
The system is off a combi boiler. 22mm ring around the house with 15mm drops down or up to each rad. Would this be a good idea?

I know this may restrict flow (as on standard isolation valves the opening looks about 10m) but on the rad TRV’s and shut off valves, the opening too looks only to be 10mm csa.

Any advice would be appreciated.

[gas man]

no not a good idea isos or ballofixs can leak trough the center better to put the drops in their desired position and use cap ends

[Puddle]

As said would not put valves in
You have a combi system so quick to drian down,put good drain point on and by the time you are sorted to connect rad pipework runs, as you go along, required pipework will be drained and ready to connect up,and another 10/15 mins to refill,you are going to have to fill the new sections anyway