DPM first or insulation?

[elsmore1]

I am getting some ready mix concrete for a conservatory base and have got some insulation and a damp proof membrane. My question is do i put the DPM down first and insulation on top or vice versa i have seen both done!

I assume the damp can get in the insualtion if its below the dpm and also dont think the concrete will damage the insulation so i am tempted to put the insulation on top of the DPM.

Any advice will be helpful

Thanks

 

[ashymoko]

youve just answeredyour own question, go for it mate thats the way i do it and the building inspector loves it!!

 

[PrenticeBoyofDerry]

I build form work for base, crushed and wacker hardcore, lay insulation and any service if needed, pour concrete then DPC before brick work.

 

[elsmore1]

I have built most of the base already I dug strip footings and 3 courses of brick on top, inside I have put down hardcore and topped with sand to make it soft on DPM, so bsically I have a hole in the middel to fill with concrete and insulation.

I think I will go with DPM first and insulation on top.

 

[PrenticeBoyofDerry]

So your laying DPC then insulation Celotex/Kingspan then a pour over that.
If so got you, misunderstood first post soz!
Have thought about reinforcement.

 

[elsmore1]

Yes I will now lay the DPM on top of sand then some insulation I got from the builders merchants then pour concrete on top, but I dont really think I need any reinforcement, though I did add some mesh to the strip footings.

 

[freddiemercurystwin]

Make sure you tape the joints of the insulation or lay a membrane (125micron polythene sheet) over the top of the insulation to stop any concrete seeping into the joints.

 

[elsmore1]

I have a sheet 4m x 15m so I can lay the DPM in one go!

 

[drnail]

yes u can if its big enough remember to overlap ya bricks with it and cut off after

 

[noseall]

or lay a membrane (125micron polythene sheet) over the top of the insulation to stop any concrete seeping into the joints.

This is how they like it in Staffs, one under the inso' and one over.

 

[Chukka63]

like everything these days,belts n braces n then double it before doublign it again.that goes for everything not just building

 

[elsmore1]

Nice advice I have laid the DPM today with the insulaltion on top and need another sheet as I am a bit short, thats because I gave dimensions in metres and sheets are in feet, I will then add a sheet of DPM over the top too to make an nice insulation sandwich!

 

[Chukka63]

i prefer ham in my sandwich

 

[Deluks]

i prefer ham in my sandwich

Fat is also an insulator

 

[geraint]

or lay a membrane (125micron polythene sheet) over the top of the insulation to stop any concrete seeping into the joints.

This is how they like it in Staffs, one under the inso' and one over.

depends on the insulation. only require above with some.