Building your conservatory foundation
Excavate the conservatory foundation down to solid ground a minimum depth of 900mm (2′-6″) and cast the concrete foundation a minimum depth of 200mm (8″). This is the minimum depth of concrete. Once the concrete has set, normally overnight, build the brickwork up to the height of the existing house foundation. The next stage is to backfill any earth to fill all the voids and to hardcore the entire floor area to a minimum depth of 150mm (6″) and compact using a vibating plate compactor, sand blinding about 25mm (1″) is added to prevent the visqueen sheeting vapour barrier from being damaged, this is also compacted using a vibrating plate. Lay 1200 gauge visqueen sheeting to the total floor area and over lap to cover your new brickwork to prevent any staining by the concrete. The concrete floor is poured using premixed concrete, this can be mixed on site by a barrowmix service and you only pay for the amount of concrete you use. Leave the floor a couple of days to set and then you are ready to build the dwarf wall for your new conservatory.
For speed of construction you can mass pour the foundation to 4 – 5 course’s of brickwork below the existing house foundation, the additional cost of concrete will be outweighed by the saving of materials and labour to build up to the same height.
July 5th, 2006 at 1:59 am
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September 12th, 2007 at 3:35 pm
i am buiding my conservatory on a concrete floor. can you tell me the best way to build up from the concrte floor? the dimension from the house floor to the garden concrete floor is 20cm. is that enough for the foundation? please let me know if you have any diagrams to show how i would resolve this….thank you
January 15th, 2008 at 12:24 pm
Hello wondering if you could tell me something we had a conservatory built last august when they did the base they put the concret over soil nothing else they they dug a lot of soil away but they did the wall before they put the concret in as it is a raised floor to meet my kitchen floor they put a timber floor down as they was doing it my husband had said to them is it alright to put under floor heating and travatine tiles down he said yes fine mt husband waited about 4 weeks then started to put the under floor heating and tiles down when it was finished sat back and enjoyed it for a few weeks then we noticed tiles cracking seems to be were the joining of the wood floor is somebody came last night from the company after waiting 7 weeks said he would have a word with his boss can you suggest anything what as happend thank you christine.
January 15th, 2008 at 12:52 pm
Hello Christine
Is the cracking of the tiles where the new timber floor of the conservatory meets the existing house timber floor ?