Flat Concrete roof/veranda

[PAR1969]

Hi we are in the final stages of renovating our house, we are now turning our attention to the flat roofed veranda - underneath this is a pool, which has not been used for sometime due the condition of the room it is in.  The current flat roof has leaked for a number of years and we are now looking to replace it.  I would welcome you suggestions about the best way to water/weather proof this area - it will be used a lot so not just a roof. I have attached a photo so you can see the scale of area I am talking about .

[Onoff]

What's the existing tooc finish, hot laid asphalt I'm guessing?

 

Although the rectangles you can see suggest 8'x4" boards underneath?

Edited June 24, 2018 by Onoff

[PAR1969]

Hi thanks for replying - Im not really sure the previous owners said they had it replaced about 5 year ago - looks like mesh and concrete then some sort of sealant painted over it.  The sealant is peeling to the point you can see the mesh underneath.  Our builder is looking to do a similar repair using top of the range products (the previous job looks like is was done very poorly) - but  I wondered if there was alternatives that are going to be long lasting.

[Ferdinand]

You could isolate the terrace from the roof using this sort of system. There  are various types around, and they are not especially expensive imo.

 

 

 

Edited June 24, 2018 by Ferdinand

[PAR1969]

Thanks  how would we stop the elements getting through the slabs.

[Jeremy Harris]

1 hour ago, PAR1969 said:

Thanks  how would we stop the elements getting through the slabs.

 

You put an impermeable membrane, like EPDM or GRP on the roof, then fit the stand offs and paving.  Water runs down through the gaps between the load-bearing slabs and runs off down the drains/gutter.  The big advantage is that there is no wear and tear on the waterproof layer and also the waterproof layer is protected from damaging sunlight, so will last for many decades.

[ADLIan]

Should also take the opportunity to add/upgrade the insulation. Probably falls under Appr Doc L1B requiring this upgrade.

[Onoff]

Does the roof fall to a drain point (s)?

[Ferdinand]

10 hours ago, JSHarris said:

 

You put an impermeable membrane, like EPDM or GRP on the roof, then fit the stand offs and paving.  Water runs down through the gaps between the load-bearing slabs and runs off down the drains/gutter.  The big advantage is that there is no wear and tear on the waterproof layer and also the waterproof layer is protected from damaging sunlight, so will last for many decades.

 

You you can also have a reasonable fall on the roof itself, as you can get levelling shims, or even self levelling supports. They can cost as little as a couple of ££ each, and support several hundred kg or more if a heavy duty version is used.

 

I have my patio on these since 2014, and I am waiting for 8 to arrive to give me an adjustable shed base as the ground keeps compacting and my shed looks differently drunk every year.

 

If you are of an H&E or Hampstead mindset, you could save money by having an open air pool .

 

F

 

Edited June 25, 2018 by Ferdinand

[PAR1969]

We are in Scotland - no chance of an open air pool. ?

 

On/Off

The Roof does have a drain point.

[Ferdinand]

9 hours ago, PAR1969 said:

We are in Scotland - no chance of an open air pool. ?

 

On/Off

The Roof does have a drain point.

 

There is somebody here somewhere with an open swimming pool. It might even be in Scotland.

 

Unfortunately no evidence is to hand ?, so I have no case to make for your being insufficiently hard.

Edited June 25, 2018 by Ferdinand

[Onoff]

7 hours ago, PAR1969 said:

On/Off

The Roof does have a drain point.

 

OK. Can the one drain cope with the run off?

 

There's given litres per minute that a certain size rain water outlet can handle. A given roof area requires "X" drainage capability. Was yours properly designed or done ad hoc etc. I've seen roofs leak where the drain can't cope and there's a poor detail where the roof membrane interfaces with the rwo. It can then track miles under the waterproof layer and appear inside the building nowhere near the drain. Or it runs along services in a suspended ceiling etc.

[PAR1969]

Hi I will take a look when I am there today. If I can remember there is only 1 drain point.

 

Was hoping there may be someone on here with a similar set up that might have a leak proof roof.