Problem of water seepage from poorly plastered wall

[zahid]

I have an interesting problem of water seepage. Request the experts to suggest ways to fix it.

When I started construction of my home, there was a home already present at the back of my site ( both are 30 x 40 sites).

That person had used entire space for 10 feet (wall on his site's edge) without any set back. Rest of 20 feet, he had left 2 feet set back on the ground floor only and brought the wall back towards my site, starting from first floor. There was only 1/2 foot space between his backside wall and my site, for the rest of 20 feet. So, out of 30 feet common with my site, he hadn't left any set back for 10 feet and 1/2 foot set back for rest of 20 feet.

My engineer suggested wall to wall construction for 10 feet (attached to neighbor's wall) and extend the same wall for 5 more feet (total 15 feet full space utilization). For the rest of 15 feet, a set back of 3.5 feet was left, for good ventilation.

Now, since there is just 1/2 feet gap between my wall and my neighbor's wall (for 5 feet length), the masons could not properly plaster my wall, on the exterior. Whatever little plastering was possible while constructing the wall, it was done. But remember that it wasn't perfect plastering, for 5 feet length of my wall.

Problem: Whenever it rains heavily, the water enters the 1/2 feet gap between my wall and my neighbor's wall and percolates to the inside from poorly plastered portion, damaging the interior paint of my home. Problem is especially bad over the 5 feet distance, where there is no wall to wall attachment and a gap of 1/2 foot is present.

Request to the experts on this forum is to suggest some solution to this problem. Is there any water-proof paint or any other substance that could be spray painted on the exterior side of my wall, on the poorly plastered area, where the 1/2 foot gap is present? Is there any other suggestion to avoid water seepage?

[Nivas]

1/2 foot gap is too less gap to be painted with brush or roller . get hold of insecticide spraying gear from garden stores , ask for penetrating siloxane sealer for masonry surface or get few litres of Dr Fixit Repellin WR or Fosroc Nitocote SN522 , spray generously and saturate the un-plastered surface. repeat and give multiple coats.
This will make the external surface Hydrophobic and water will not penetrate. water will roll off the surface, penetration will be arrested.

In general , try not to butt the wall , masonry surfaces need enough surface area to breathe. even without rain , it can wick atmospheric moisture and cause molding and algal growth and destroy your inner surface ,rain makes it worse.

[ardesarchitects]

Hi Zahid ,
Rather than trying to repair in a location that is not accessible its better to work at the source point of rain entering between two buildings.
My suggestion is to close the 1/2' gap at the parapet wall level of your building from neighbors, its easy if neighbor house is higher than your parapet wall other wise you request him to get it closed with a granite stone slab so that the water will just drain on to his terrace or your terrace .

Regards
Ar.Praveen.N
Ardes Architects and Interior designers
ardesarchitects@gmail.com
https://www.facebook.com/ardes.architects
http://www.ardesarchitects.com

[zahid]

Thank you, Nivas & Praveen, for your responses. Much appreciated.

@Praveen - In this case my parapet wall is at a higher position than my neighbor's parapet wall. But as you have suggested, closing the gap seems to be a good option. Would it be ok to use a fiber sheet, which could be fixed to my wall, with a slope towards my neighbor's terrace? Granite slab can be placed only if both parapet walls are almost of similar height, which is not the case here.

If closing the gap doesn't work out well, then I have to try out the suggestion given by Nivas. Thanks, again.

[ajaymathewp]

THE SIMPLEST SOLUTION WILL BE TO HAVE A CANOPY FIXED ON YOUR PARAPET THIS WILL AVOID ANY RAIN WATER FROM FALLING ON YOUR AFFECTED WALL .