PVC front porch DIY

[GeorgeD2]

Hello guys.

I have purchased a second hand PVC L-shaped porch to be installed into the existing recess (Please see pictures).

I have few points I would like to get some advise on please.

1. There is a layer of 9-10 cm concrete where the porch will go ( picture attached)

What kind of additional base would I need to have underneath the porch? The PVC frames will need to be screwed into the base. Is there any waterproofing I need to be applying under the base, or between the base and the PVC frames?

2. Here I have a diagram of a typical porch. At the bottom, between the brick and the PVC frame there is a Cill. Could you advise on what that cill is, as I cant seem to find it anywhere. Maybe looking for a wrong thing.

3. When I am fixing the porch to the walls, is there anything I need to be putting between the PVC and the wall? The walls are not smooth and the frames will not go flush. Also how do I finish off - seal, the PVC to wall junction?

4. And finally, do I need to think of any vents to make sure the porch does not accumulate damp? Is there a generally accepted rule on that?

Thank you in advance.

George

 

[Notch7]

https://www.eurocell.co.uk/trims-and-cills/window-cills

Im not sure if cills are profile specific....

I expect you realise that building onto an existing external ground slab is a compromise.....you might struggle to stop water running across the slab and creeping underneath.
Damp arrangements are a bit tricky -but you should be able to minimise risk with some advise on this forum.

My guess is that the frames wont be strong enough and will need corner posts.

where you fit to the wall, leave a bit of a gap, pack out with frame packers or similar. Then once screwed on, fill gaps with foam or silicon and cover with trims.
You may wish to consider a vertical dpc.

 

[GeorgeD2]

Was hoping to avoid concrete demolition. But if that`s the case, then I may have to stick to the proper way of doing it. So I would need to remove the existing concrete and build a foundation for the porch?

My guess is that the frames wont be strong enough and will need corner posts.

Where the two frames join at a right angle, there is a UPVC post with a metal reinforcement inside. I am assuming that could be used as one of the posts? How many more posts and at which positions would you suggest to place them?

When talking about the strength of the frames, do you mean to hold the roof?

Thank you!