Planet Springwell A Personal Guide To Building Your Own Conservatory

Foundations
Building a dwarf walled conservatory (and possibly a full length version) is very much like building a full blown extension, in that the conservatory has to have foundations, damp proof course, a solumn, etc. Therefore even before the conservatory arrives and can be put together there is a fair amount of work to be done. I was lucky enough to have a good relationship with a local builder who was willing to carryout all the foundation and dwarf wall work the two weeks prior to my conservatory arriving. Before my builder could even start i had to prepare the area that the conservatory was going to be built. This involved removing excess soil and some old clay pipes, ensuring all areas of the existing property that would be affected by the construction were in good condition as some part so the building would be harder to reach once the conservatory was in place. Now starts one of the most critical areas, construction of the base the conservatory will ultimately rest upon, slightly too long or too wide and the conservatory will not fit, therefore i followed the dimensions on the base plan provided by Carlton to the millimeter. I knew the first chance i would have of checking anything was when the conservatory actually arrived and it would be to late to change very much of the base then. To construct the foundations a ditch approximately 600mm in width and 200mm deep was dug to allow concrete to be poured into where the conservatory dwarf walls would be constructed. We purchased sand, cement and 10mm gravel and mixed the concrete ourselves using a cement mixer. Steel reinforcement mesh was placed within the cement to provide the neccessary lateral strengthening. The area inside the foundations (the solumn) was then filled with 10 and 20mm gravel covered with a layer of sand with a damp proof membrane then placed on top. Concrete to minimum thickness of 50mm was then poured onto the membrane to create a solid base. Its important to note that the total height of the conservatory solumn must not be higher than the solumn of the existing property otherwise (as i understand it) there is a danger of dampness as water likes to travel to the lowest point i.e. try and keep the solumn of existing property and conservatory at the same level. The concrete was then given a few days to harden before any construction carried out on it.

The dwarf walls were built on from two rows of standard 100mm blocks seperated by approx 75mm and filled with 60mm thick insullation sheets. Tip: Enusre the walls are built exactly at 90 degrees by not only measuring the length of each of the sides but also checking the diagonal distances are equal as required. Note that the conservatory sits totally on the outer brickwork, the inner blocks only provide a cavatity for insulation and windows sills and floor (if joist hangers are to be used). My dwarf walls were built to a height of approx 525cm from floor/joist height.