Dwarf Walls in the Attic Rooms.

By Andy the stuff doer

So I’ve got a roof on the wash house,  I can now get a boiler in, the pipe work is laid through to where it needs to be.  So at first glance it doesn’t seem such a big step to get the hot water flowing and the central heating running.  However the radiators need fitting and to do that that you need walls to hang them on.

This post covers what needed doing to get to this stage in the attic rooms. I’ll have to write another post for the copper radiator and fitting radiators to stone walls etc.

Dwarf walls are those that fill the bit between the sloping roof and the floor.  They provide a great space to hide services, electrics, plumbing, ventilation or if big enough a bit of storage space.

Services in the space behind the Dwarf Wall.

services behind the attic dwarf wall

Wiring and plumbing all needs going in first before the dwarf wall is built

Before I could construct the wall all the wiring and plumbing etc. had to thought through and installed. So lots of decisions on where the radiators are going, where the sockets need to be, what ducting is need for the ventilation system (more on that later) and even how the arial cables need to go.   Then of course it all need to go in, after considering how the space is going to insulated.

This fist picture shows the stud work and wiring with a 40mm sleeve of plastic waste pipe over it as it will be passing through rockwool type insulation.  This gives it air space around it so the wires won’t overheat if the load through it is up to the max (in this case 16 A on 2.5mm).  If it passes directly through encased in insulation the circuit would have to de-rated or the cable size increased.  The copper pipework at his point is down to 10mm diameter to each individual radiator after splitting down from 15mm. The 10mm is easy to bend by hand to get it to the required position.  To know what the right position was I temporarily mounted the radiators.

Next comes the insulation after thinking about how the space will be ventilated to ensure any condensation can evaporate away.  The roofing membrane is breathable but the insulation need to be kept away from it so there is a good gap for air flow.  As the insulation is packed in quite tight I stapled some strips of left over membrane on to the rafters where necessary to hold back the insulation.

insulation behind dwarf wall in attic room

The space packed with insulation but leaving an air gap for ventilation

The whole face of the wall is then sealed with a vapour barrier.  This is to minimise moisture that could enter the space from the bedrooms.  I had considered laying this on the floor in the space as well to stop moisture from the rooms below but considered it impossible to seal at the eves, therefore making it ineffective as a moisture barrier and probably restricting natural evaporation.

vapour barrier behind dwarf wall in attic room

Sealed to prevent moist air from the room entering the space

The pipes, wiring, back boxes and ducts have to be carefully detailed as they pass through the barrier.  All this provides the added benefit of improving air tightness making the ventilation system more effective as well as reducing energy sapping drafts.

The timber panelling could then be fitted followed be skirting and any trims.  The panelling is recycled from various bits from the strip out.  This should be more stable new bought stuff that no matter how long you leave it to acclimatise always seems to shrink as soon as its fitted.  On the downside I had to heat gun strip many layers off before I could re-use it.  The joints are corked with decorator’s cork that will hopefully hold the paint whilst still allowing the timber a bit of movement. 

reclaimed panelling on attic dwarf wall

Reclaimed panelling on attic dwarf wall and new skirting board

All this was very time consuming considering the job was to get the radiators fitted. But it needed doing at some point and now it is, apart from sanding and painting.   So that’s a job for the next weekend and then I won’t have to drain and remove the radiators to paint behind them at a later stage.

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