What should I use to fill the gap between my door frame and patio?

[Jared Ba]

Hello All!

I've noticed a damp on my concrete floor coming from under the front door, so had a look and there is a huge gap between the tiles and the threshold as seen in the pics.

Obviously I would need to fill it out with something that is waterproof to stop the damp. What would be the best material to use? Silicone? Mortar? Or something else?

I'd really appreciate any product or technique recommendations to rectify this.
Thank you!

 

[Ian H]

You could try and point it with something but I think the floor outside it too high.

 

[Safety First]

I am an expert at overthinking, procrastinating, and being wrong...
So with that out of the way...

More pics please, from further away and from the side... and what's the rubber strip to the RHS?

What kind of coverage is there from eaves? Is this exposed to driving rain? Is there a fall going the wrong way- towards the house?
If no to both, then I was considering that as well as an entry route for moisture, the gap will be offering a drying route also, which might be the preferred route to drying through your floor. Maybe leave it open.

If there is a good fall going in the right direction on those slabs, and a lot of rain is slung at your front door, then a strip of CT1 would function to carry the water from cill to paving stones...
You could use cement but if the cill moves a lot with being walked on, then it may just crack in time.

 

[Jared Ba]

Hi, thank you for your replies guys I do appreciate it!

The Rubber strip is a door mat In general the roof covers the gap, although if there is rain and wind some of the water finds it way there.

The gap is 1.4 inches wide and it is 2 inches deep.

Would it be best to use cement as base and then cover it with CT1?

Is that the product you are referring to?

https://www.amazon.co.uk/CT1-Sealant-Construction-Adhesive-Colours/dp/B00F8CK7T4

Thank you!

 

[Safety First]

Blimey, if it's that deep it'll be pretty strong. So maybe, yeah, mortar then a sealant. Or maybe just mortar, if its falling away from your floor sufficiently....i.e.,
If you have standing water you obviously need utterly impervious materials to hold the water- as it's got to evaporate itself away. Introduce a slope-falling away in the right direction and you can afford to have something more porous. I.e. concrete roof tiles work not by being water proof as such, but offering a shedding surface....

CT1 is good for tying one shedding surface to another, and being flexible with it.

Look at the gap, imagine if it was not there- was solid and level with the slabs-adjoining material; would the water run away? If so, fill the gap with cement and smooth the surface to make a slight slope away from the door cill.

 

[Jared Ba]

Thank you very much for your help! There was a tiny gap between the sill and the door frame which caused all the issues. I filled it up with builder silicone and there is no more damp. Thank you again! All the best!

 

[foxhole]

The gap is not causing issues, the exterior level looks to be at least 6” too high , should meet below the dpc which would usually be two bricks below the door sill.
The dpc has been breeched causing damp penetration .