Rat proofing a deck at the construction stage.

[Wingedharpy]

I appreciate some folk may think we're mad in view of recent bad publicity regarding decking and rats but, despite this, we are currently in the process of having composite decking laid.
Any tips on what we can do to diminish the potential of rats and/or other vermin nesting underneath the deck?
I'm looking for advice regarding construction rather than lifestyle.
We don't eat outside and will not be barbecuing on it.
DH has been given a stern talking to regarding feeding birds.
Any other advice much appreciated - just don't say "don't do it!!!"

You'd need a full solid concrete slab basically overlaid with wood with no gaps...

Scrub regularly as in the UK climate, wood gets slippery within a season. That is why yacht clubs often have chicken wire nailed to pontoons.

...that would have made sense until i spotted that you said ' composite'. Sorry - ignore!

I put poison under ours once a month. It's been down 2 years and have seen them twice in that time, both times when I had forgotten to put it down.

Solid concrete slab not doable I'm afraid as this will be an upside down L shaped deck along the side return of a terraced house and the Victorian drains run the length of this underground.
It is a public drain too so would require consent from our water supplier and costly paperwork submission making the project a non-starter.
I'm thinking, rightly or wrongly, that the sides of the deck will be reasonably well rat proofed as it will sit between the side wall of the house and the boundary fence.
There will be a decorative loose stone pebble infill along the fence side so I'm thinking rats won't want to dig into that as it will be unstable and will just collapse in on them as they dig.
Would filling in all the outside "cells" of the decking substructure with engineering bricks be enough to deter them?
DH says I'm overthinking this and should stop reading!

That's interesting Frouby.
The contractor said he would put several pots of poison down before he decked over the frame.
I'm just keen to do any prevention work that we can do at this stage rather than killing them once they've moved in so they then decompose underneath.
The Jack Russell who lives on the other side of the fence should also help keep me safe on that side!

If a rat's determined it will get through any gap - I watched one squeeze through a gap just over a centimetre diameter, and they can burrow under walls etc.

1.5cm gap is all they need P1P0ppy and the b*ers can burrow up to 3 feet deep!
Digging a moat around the deck won't help as they can also swim.
Once they've learned to drive a car, we'll all be doomed!

I would make sure you have a way to access beneath the decking and keep a ratbox there which you can replenish with poison regularly. It needs to be a proper lockable box.

It seems to be working for us. Plus we have a very keen whippet who does let me know if we have an issue.

We have horses and keep numbers down at the stables by constantly having poison down. Apparently they have made runs under the concrete of the yard and stables.

You will always be a few meters away from them and no sooner have you got rid of one another will move in its space. So I have always worked on poison being the best option.

They apparently build up immunity but it probably works enough to keep them away by poisoning the very young or pregnant females.

They are determined buggers and descendants of Houdini too!

I'd be worried giving them a nice home right next to my house will encourage them to look for a way in

As well as outlawing rat bird tables full of delicious rat bird food, and black bags of rat food kitchen waste, look for sources of water, such as garden ponds, leaky pipes. They need constant access to water.

I suppose you could have some trapdoors so you can tip in poison easily.

Had mine 14 years and never had a rat or a mouse. I think this rat nest theory has been blown out of proportion

sluj, you have given me hope.
Do you do anything in particular to deter them or not?

PJ. - We don't have a garden pond but do have several bird baths.
DH will not get rid of these as he has a touch of the Bill Oddie crossed with David Attenborough about him.
Looking after the wild birds gives him such pleasure - he has blackbirds and robins coming to the back door to look for him if he's a bit late going out with their food.
There is no food waste hanging about anywhere.
There will be a trapdoor over the manhole cover for access should it be required so we could use that to put in fresh poison.

I should say, I have never seen a rat in all the years we've lived here but I don't want this construction to encourage them.

Nope, nothing special. It's quite a big void underneath mine as it levels up a drop at the end of the garden. Maybe 3 feet in places? It's also up against a fence so plenty of holes for things to get down.

I'm looking to replace it with a composite deck at some point myself so would be interesting to hear how you get on.