Once plastered internally the room will be ready for its second fix (socket fronts, doors, skirting boards etc) and final décor although it must be mentioned that the room and any plastering work be allowed to dry completely beforehand. Floor screed dries at the rate of about 1mm depth per day as does plaster. A 3mm plaster skim will need around 2-3 days and 50mm of floor screed around 6 weeks, (less time in summer, it all depends on the relative ambient temperature and humidity). Some ‘thin coat’ type screeds will need to be covered over for a period of time to allow the mix to ‘cure’ properly, if advised this will ensure the screed stays put and does not crack or crumble.

One reason for allowing it to dry is that introducing unfinished softwood into the room before it has dried will result in twisted / deformed timber, particularly noticeable when using hardboard / ply faced hollow doors with softwood edging. The doors will twist noticeably. Laminate flooring will suffer a similar fate if installed on a damp floor.

Once it has dried its safe to crack on and a good method of working is to paint the ceiling and walls before installing any woodwork or electrical socket fronts. This just saves on cutting in. Some have even been known to give plaster coving a couple of coats of paint before installing it for the same reason, then its just a final coat and touch up the corners. The same can apply to painted woodwork such as skirting boards and architraves, undercoating and glossing lengths of timber supported on a couple of tressles is easier than shuffling round on your knees 3 times round the room. Again, just caulk in any gaps and touch up once installed.

When painting newly plastered surfaces a ‘mist’ coat must be applied first. Applying neat silk paint onto a newly plastered surface will result in the paint forming a ‘skin’ on the plaster and is easy to peel off. The ‘mist’ coat soaks into the plaster and slows down its rate of suction when it will absorb water from the paint. Matt paint is ideal as it is inherently ‘breathable’, in fact the same white matt used on ceilings is ideal for the walls too when watered down. A good 70/30 paint / water coat is needed or 2 coats of 50 / 50. Once dry any colours or finish may be applied according to manufacturers instructions. A mist coat will also help to show up any imperfections in the finish so any sanding can be done before the top coats are applied.

Skirting boards and architraves can be either stuck on with ‘no nails’ or screw fixed into the timber battens. They can also be masonary nailed or screwed onto a solid plastered surface. If a timber floor (laminate, engineered timber flooring etc) is to be installed then this is best done before any architraves or skirting.

Doors are hung as per normal ensuring building regulations are followed with regard to access for the disabled (door width etc) and fire regulations if applicable.

Electrical socket fronts can now be installed and the circuits tested by a qualified elctrician. This is where the ‘part p’ qualification comes in. Any new additional ring main must be installed and tested by someone qualified and registered to do so. A copy of the test certificate is issued to the council, the NIC (electrical regulating body, like corgi for gas) and the customer. The building inspector will need to see a copy of the certificate before he signs the job off as ‘complete to a satisfactory standard laid out by local authority building control’ and again, you will get a copy of this ‘sign off’ notice. You will need these certificates should you come to sell your house as proof of work carried out to the required standard so keep them in a safe place.

Fitting the radiator is a job best left till last. Or at the least, after you’ve painted the wall. It’s perfectly possible on first fix to re-light the boiler leaving the radiator valves in the off position with the radiator unconnected. This then means you can get on with the rest of the build without covering your shiny new radiator with plaster and paint. All it means to a plumber is an hours work including repressurising a combi system. Some old gravity systems however, can be a large pain to bleed through and it may require a bit of persuading. Be careful of flooding a floating floor too, remember it really is a floating floor once the cellotex and chipboard are floating on half an inch of water. Also remember to do your heat loss calculations when purchasing a new radiator. If you currently live in a house 10 or 20 years old or more you’re probably going to find that this extension requires about the same size radiator as is in your downstairs loo due to the extra insulation…. Means less money to buy and less money to run and also takes up less space. If you take your room dimensions and the insulation spec into your plumbers merchant, they will most probably be happy to work out the size of radiator you require. You do not have to be a corgi registered heat engineer to fit a new radiator although it does help significantly if you have some good plumbing experience. Even some experienced plumbers get a leak from time to time so double check everything, and again a few days later, especially if you have a floating floor.

If your left with a rather unsightly electrical consumer unit or gas meter it may be worth regarding a ‘kitchen unit’ as an ideal solution. Larder, wall and floor units are all readily available off the shelf at most diy stores, are cheap and easy to assemble and can be purchased with the relevant ‘décor end panels’ to replace the standard white melamine carcassing. Choice of doors and ‘voila!’ you have your ‘leccy cupboard’

This is probably not the best time to check if your snooker / pool table will fit down the hallway and through the door but if not you can always swap with the kids…