When it comes to Conservatory measurements and setting out the slab it is extremely important that you don't get the incorrect information.
It must be square to the house with accurate dimensions to accept the DIY conservatory frames. We recommend that you measure at least twice for every stage of the process. The information below is for general guidance only to help you to select the size of conservatory that you require. When measuring your site, please bear in mind the following:
1. All Conservatory sizes on this web site are in mm.
2. All Conservatory dimensions are internal frame sizes.
MARK OUT THE SITE
If you are using a builder or ground works contractor to perform this task then they will probably bring along state of the art measuring tools such as laser levels and theodolites. However you should still peg out the site during the planning stage to give yourself an idea of how large the proposed conservatory is going to be and how it relates to your house. All you should need is a ball of string and some pegs, a spirit level and a straight piece of timber about 3m long.
Please bear in mind from the start that your self-build conservatory is designed and manufactured to great precision and will fit together accurately. Providing that the base is built correctly dimensioned and level, the only on-site sawing or planning should be for any items that butt against the host walls such as gable horns, fascias and trims.
CHECK THE HOUSE WALL
Before you start work on the slab you will need to profile the house wall by assessing how upright and level it is, particularly with older properties where the wall could be falling towards or away from you. If it is falling away then it is a simple matter to pack and seal the gap when the conservatory is offered up. Should it be falling towards you then the slab needs to be bigger to take account of the discrepancy at wall plate / wall rafter level. You can knock in some masonry nails at the requisite height and test how vertical it is by either using a level or a plumb line.
LOOK FOR HARD POINTS
To find any obtrusive hard points, as frequently happens in stone or cob cottages, place a plank of wood at wall plate / ridge height to see how true the wall is. Set your base line from these wall reference points and measure out the slab from that point.
DOUBLE CHECK HEIGHTS
Finally, double check the height of the proposed Conservatory and ensure that there is enough room to install lead flashing. Aim to have at least 200mm (8") of space between the highest part of the roof and any obstructions such as first floor window sills.