New decking and waterproof membrane

[Bertie.G]

Hi everyone. I'm looking for some advice please.

I am looking to add some composite decking just outside the kitchen backdoor. I have removed the old patio slabs all around the house as they were at level with the damproof membrane and it wasn't slopped either (I didn't do it, it was here before I moved in).

Now I have mixed advice from a variety of people when it comes to laying the new decking.

1. Some advise to lay the decking on top of the concrete, but doing so it will raise the decking above the damproof. To counter that they have advise to create a gap between the house and the concrete slab to allow water to drain through. Some advise that it's not a good idea because now the foundation receives more water and it concentrates more around the foundations and just leave it the way it is.

2. Remove the slab and start fresh with just the decking at a lower level than the damp proof. But now there is nothing stopping the water from moving away from the foundation. The concrete slab was acting like a protection from water. Is that true?

I got confused the more people were giving me advice (mostly family members with some building knowledge. Don't get me started!)

What would you do? Thanks in advance!

P.s. the gap is there because I had the old extension extended to the side, in case anyone is wondering.

 

[He who knows]

Think about this idea that you need the slab to "protect" the foundations.

That would mean you'd never see houses with flowerbeds or grass right up against them. But you do.

The plus of leaving the concrete is less work and a solid level surface to put decking down.

The minus is that it does nothing to improve drainage, which is an important consideration as we get more, and more intense, rainfall.

IMO removing it is the best option.

If you hire a saw like this:

you might be able to leave pads to support the decking bearers, in the same way that people often build pads when installing a deck.


And do some research into the longevity of composite decking, particularly if you have a dog, or move furniture/BBQs about, and colour fastness.

 

[zaydenwood]

If you love to bbq, nothing is better than having a built-in kitchen on your deck. These are perfect for entertaining guests. My Home Handyman is the right place