How to prevent rain water flow through vents?

[approachmhn]

 

Hi,

when it rains heavily I see dampness under the house where these vents are located. 
can someone please suggest on how to avoid water flowing from top getting into the vents.

TIA.

[MitchellMc]

Hi @approachmhn,

I'm surprised that you'll see too much water entering these vents. Is there a possibility that the moisture is gaining access to the rear of that wall from somewhere else?

Preventing water from getting into them should be a relatively easy task. I'd recommend adhering a thin piece of aluminium angle above their top edge. This will become a drip ledge and prevent water from running over the face of the vent. I suggest rounding over the exposed edges with a file to prevent anyone from cutting their legs on them.

Please let me know if you have any questions.

Mitchell

[approachmhn]

Hi @MitchellMc ,

Thank you for your suggestion.

I was thinking water entered through vent because of heavy rain 2 weeks back. After reading your comment, I did go around and checked till the other end, and I noticed there is moisture throughout the wall end.

I believe this is because the land is sloped and this wall is on the lower side. Attached photo.

Few months back, Engineer advised to put agi drain on the higher side of the land When I checked with plumber, he told not sure how deep is subsurface  water. And can’t  guarantee if agi drain helps.

only when it rains heavily or continuously drizzling for a day nearly, i see there will be water.

can you please suggest if there is any alternative to stop subsurface water.

it’s almost 2 weeks from last rain and I still see moisture.

Thanks

 

 

[MitchellMc]

Hi @approachmhn,

Although there might be some water coming through the vents, I'd suggest it's water coming under the slab and surfacing under the wall. No drainage expert can guarantee something will work, but it's about minimising the amount of water that can flow to a point. Any drainage will help.

Does rainwater pool on top of the driveway against this wall when it rains? If so, you might like to go over the joint between the wall and the concrete slab with Sikaflex to ensure it is sealed adequately. You could then consider painting the driveway. The addition of drainage and sealing the wall to the concrete could help with the amount of water that is gaining access to the house. You might also like to consider installing additional wall vents to improve sub-floor ventilation allowing the space to dry out quicker.

Mitchell

[approachmhn]

Thanks @MitchellMc 

the slab next to wall is sloping away from wall. So no water polling. 
I will still make sure to seal with Sikaflex as suggested.

Also top of the patio is fully waterproof. 

I am thinking of 2 options

1) install agi drain on higher end of the house (mentioned H in house map) 

OR

2) install agi drain under the house I.e rear of the wall and connect to storm water pipe.

Not sure which is better to go with. 
Appreciate any advice on this.

thanks. 

[MitchellMc]

Since the moisture is around the wall, I would think it's more likely that it's coming from outside it rather than the other side of the house—unless you've seen water migrating from there. I suggest drainage should be placed on the other side of the driveway or at the front of the house. If the water was coming from H then I would have thought all the soil under the house would be wet.

Mitchell

[approachmhn]

Thanks @MitchellMc for the detailed suggestions.

i will start with sealing first. Then start with front of house. See if it works.

And then look at drainage on other side of driveway if above doesn’t solve.

I will update as I progress.

definitely soil under house is not wet. It is only rear of the wall as seen in picture.

[approachmhn]

Hi @MitchellMc ,

I am very happy and relieved to inform that I found one source of water on the higher side of the house. 
just dug around the old disconnected clay pipe and found this open T junction. When I hose down water into it, after 5-10 mins I saw water pooling on one corner of l lower side.

Still a lot to dig as I see pipe going further but wanted to share this.

Thank you for your guidance.

will update as I progress.

 

[EricL]

Hello @approachmhn 

Thank you for that update, it appears to be terracotta pipes or is it metal? If it is terracotta please take care as they are easily broken if hit with a sharp tool. 

If you need further assistance, please let us know.

Eric

[approachmhn]

Thanks @EricL 

Yes. It is terracotta pipes. Actually all terracotta pipes connected to downpipes are disconnected and renewed with PVC.

These terracotta pipes are causing problem now when it rains. 
Shall I seal it off with cement where there is open or broken?

Will that stop rain water getting into pipe?

or is there a better solution?

please suggest.