Loft Conversion

DIpY Loft Conversion*
(*Do It Partly Yourself!)

Rendering The rendering of the outside was one of those jobs that I had anticipated farming out to a specialist. However the various specialists consulted seemed keep coming up with quotes that were more than I wanted to pay (i.e. into four figures!). Hence Trevor and I decided we would do it ourselves. Lots of sand and cement was procured from the local Wicks (their sand was half the price of the builders merchants!), a cement mixer borrowed from a neighbour, and I lots and lots of trips were made up a ladder with a 40kg bucket of muck!
In order to render onto a surface like ply, you need to cover it with expanded metal lath. This not only gives a key the render can stick to, it also integrates into the render to act as a reinforcement.	The black backing is tilers felt. This adds an additional waterproof later. The brown strips are narrow sections of 1/4" WPB ply. These hold the lath away from the surface every so often, which allows the lath to get better incorporated into the render.
The render goes on in two coats. The first is called the "scratch coat" (so called because once you are done putting it on scratch it all over so as to leave lots of indentations in the surface. This helps ensure there is a good key for the final top coat to bind to. The scratch coat is about a half to three quarters of an inch thick, it basically covers the expanded metal mesh and makes up most of the thickness of the render. The top coat will take the final finish and is only a quarter to half inch thick. We used a mix of 5:1 sand to cement, and mixed our sand 50% soft (builders) sand, and 50% sharp sand. Some waterproof PVA was added to aid workability and add waterproofing to the final render. The mix of sands give a nice mix to work with, that is easy enough to apply, but should also be more durable and less liable to crack than using just soft sand alone. It is also a better match for the other rough cast render already on the house.	The scratch coat runs down to half way down the lead flashing, and stops at a "render stop". The implement for scratching! A block of 4x2" with small nails poking out! A closer view of the metalwork that is used to make for neat corners and edges to the render. The section over the windows (and on the side of the dormer cheeks) uses a render stop so that the surface can flare out to create a natural bell shape. This will aid shedding water and create an attractive finish. The result with the scratch coat all done.
Not everything goes to plan, especially the weather! Having jut put the finishing touches to the last bit of render top coat we felt a few drops of rain... Never mind will be over soon we thought. Then it got heavier and heavier. In the end we retired inside for a break. What you see here is the result of a downpour, a wind blowing from the north (unusual in these parts), and no gutter fitted to the flat roof!	What you don't see is where all that mortar went! Straight over the windows and the back of the house below. It took several hours of scraping and pressure washing to get rid of it. The patio had to be practically dug out!
	The addition of 20% sharp sand to the mix gives a slight texture to the smooth render. A quick rub up with a sponge as the mix dries also helps add texture and remove any remaining trowel marks. The top coat on the dormer cheeks and face use the smooth finish.
	On the gable end wall, we wanted a stipple effect to match the existing rough cast render that is on the rest of the house. This is probably the simplest effect to achieve and can make even my poor rendering look quite attractive and rustic. All you need is a tamping with a stiff brush (she let me have the one from the dustpan and brush set which worked really well. The fact that I stood on the dustpan and broke it the day before might have had something to do with it!) This is the completed stipple coat just in the process of drying out.