full length glass conservatory, base help PLS

[jakk]

Hay all some advise would be good here,
What I have is a 3x3 Edwardian conservatory it is full length double glazed ploy roof (no dwarf wall)

I have read lots of different things on the net and don't know what to do.

Do I need foundations? If so how deep would people recommend?
I have also been told I may not need this because it’s only 3x3 and full length with no dwarf wall,
the patio slabs have a good base the slabs are 2x3 3" thick VERY heavy could I build on to these with a small brick 2 curse then poor concrete into the centre as a base.
Then the conservatory on top?

 

[noseall]

Yes, you could.....

 

[jakk]

thanks for your reply, is there any draw backs doing it the way i said, could it sink or fall over ? also were should I lay the damp proof ?

 

[noseall]

There is no doubt that, if slabs are laid very well then they could stand the weight of a connie.

Problems arise when you decide to change the slabs!

Seriously, if you are keen to spend money on a connie then the least you could do is afford it a decent base. Dig a foundation and lay a few courses of brick and build the connie off these.

Use solid bricks for the final course.

 

[^woody^]

No matter how good the slabs a re laid, if there is any topsoil or such like soft ground below them, then the slabs will move - such as after a wet or dry season.

Also the frame is putting a concentrated load in one place.

In principle the idea would work, but you must be confident that whatever is below the slabs, will be stable.

If there is a problem, then the conservatory wont fall down, but it will move gradually, which in the worst case, will split the frame sections at the joints, and possibly crack the DG units

Your DPM can go anywhere, but not sandwiched directly between the concrete slabs and the concrete floor - it will need a firm but softer material to prevent it puncturing

 

[jakk]

Thanks for your advice, what would be best to fix it to the house i've seen the frame fixers I was going to use them but have also noticed anchors?
They look better would that be right?

 

[noseall]

Just use regular plugs and screws. As long as you have 40mm or so of the screw & plug into masonry then you will be ok.

 

[jimbobmills]

Our patio is 18 inches thick with slabs on top. We used lots of infill (rubble) a membrane 10 inches of chips and cement for the next layer, slabs and concrete to grout it all in.

HAsnt moved at all and we put a conservatry on top. Just make sure you dont build over a sewer drain/cover as my neighbour did and the local council ordered him to knock the conservatry down. He was lucky he did that year we had so much rain his sewer pipe become blocked and flooded over... imagine coming back to a conservatry 4ft deep in it lol

 

[elsmore1]

Hi , I am building base for a conservatory 3m by 4m full height, the conservatory guy said build a strip fotting 300mm by 300mm then about a wall 3 bricks high in the centre, infill with hardcore 150mm 25mm sand, then damp course, insulation and 150mm of concrete on top.

On his website it shows them building one straight onto a patio with slabs, you can use A142 mesh too in the concrete, I have dug the hole for the strip footings now ordering the cement and ballast etc.

regards