Internal extension walls.

karltimber

Hi,

about to start an extension and was wondering about the following items.
Hopefully ye can help me with them.

Internal slabbing ? : double 4" walls with insulation in between.Some section is 4" and brick. Double block is rendered outside. Whats the best way to insulate/finish the inside walls (kitchen/utility/playroom)? sand and cement and then plastered or dab on insulated pb sheets onto blockwork or battens with insulted/plain platerboard . all with be skimmed.

Pipework? : 3/4" pipe coming from gas boiler in copper. changes to 3/4" qualpex under floor with 1/2" T's to rads in new extensions rooms.These 3/4" pipes will then reconnect to existing 3/4" system for house.
How far from the boiler has the qualpex to be ? heard about folks putting insulted pipes into 4" soil pipe under floors --any advantage ? Is it neater bringing pipes up from the floor together or at the ends of the rads ?

Gas Boiler : Will need about the 80K BTU to supply rads and heat emmersion tank upstairs. It will be internal (utility room). What makes have ye used that you would recommend. I will need to lay the gas pipe along the outside wall of the extension -from the box to the boiler. Whats this pipe called and what does it need to be housed in -- under ground.

Outside Telephone cable : next door neighbour got an axtension and looks like a new phone cable out to the old P&T junction box in the path outsude the house. What cable is used by Eircom ? Can I buy it or get from an Eircom lad ? What is this housed in -might put it in while they are digging up the garden.

Thx folks.:D

Corkey123

Karl

My preferences would be

Internal slabbing ? : double 4" walls with insulation in between.Some section is 4" and brick. Double block is rendered outside. Whats the best way to insulate/finish the inside walls (kitchen/utility/playroom)? sand and cement and then plastered or dab on insulated pb sheets onto blockwork or battens with insulted/plain platerboard . all with be skimmed.

I'd be inclined to batten, plasterboard and skim. It should help with routing pipes, cable, etc.

Pipework? : 3/4" pipe coming from gas boiler in copper. changes to 3/4" qualpex under floor with 1/2" T's to rads in new extensions rooms.These 3/4" pipes will then reconnect to existing 3/4" system for house.
How far from the boiler has the qualpex to be ? heard about folks putting insulted pipes into 4" soil pipe under floors --any advantage ? Is it neater bringing pipes up from the floor together or at the ends of the rads ?

Copper is used for the first meter from the boiler. Can't seen any advantage in putting pipes in a 4" waste pipe, certainly not under floorboards anyway. Tip while placing the pipes to the rads if it is in an accessible area put penny values in so you can isolate the rad if needed in the future. Bring the pipes upto the meeting the end of the rads. Careful measurements are required here

Nothing to offer on the other points

karltimber

anyone else got any ideas on these items.


thx folks.

The Hill Billy

Karl:

In relation to the Internal slabbing - I'd go for battens & insulated plasterboard. The insulated pb doesn't hold with dab. Also, don't see the need for a sand & cement render on the interior if you are going to slab it.

As for the pipework - I'd have the pipes rise at the the ends of the rads. Looks much neater.

Can't see any real advantage to putting insulated pipes into 4" soil pipe under interior floor. Would certainly do this for exterior pipes coming from boiler to house though.

patrido

it is common in some countries (required in england), to put buried water pipes in some kind of ducting to allow them to be removed and replaced easily. if you didn't want to go to the hassle of soil pipe, you could use 2 inch ducting or "pipe in pipe".

karltimber

Hill Billy wrote:

Karl:

In relation to the Internal slabbing - I'd go for battens & insulated plasterboard. The insulated pb doesn't hold with dab. Also, don't see the need for a sand & cement render on the interior if you are going to slab it.

question Billy -- is there a need for any insulation between the battons or a sheet of light plastic under the insulated pb ?? what thickness of insulation on the pasterboard is best/needed. normal slabbing screws (long of course) ??

thx again

The Hill Billy

No need for insulation between the battens.
You could put light plastic up, but the insulated plasterboard should already have an integrated vapour barrier.

As for the thickness of the insulated boards - depends on what type you are going for (expanded polysterene, rockwool backing, etc.). At the end of the day, you should buy the best you can afford. Shop around the builders merchants & get prices for the highest U-value boards they have.