I had my home treated for termites. Holes were drilled horizontally and vertically around the outside and inside perimeter of my garage and front porch (both unexposed to rain). After a recent unusually heavy rain fall event, I noticed that some of the drilled holes on my porch where the vertical holes and horizontal holes are in line, I have water coming up from hydrostatic pressure and staining the concrete. I’m also seeing this where holes were made into my concrete block foundation on the outside in towards beneath the slab. My first thought was it could occur if they had drilled through the vapor/water barrier which is now allowing a pathway for the water and possibly another entry point for termites. I want to seal these up with some sort of flowable concrete mix so I can fill the entirety of the hole.
I was thinking hydraulic cement, mortar fix, bonding or even sprinkling sand and cement mix into the holes and watering them down. I need to stop the water from forcing its way to the surface causing these unsightly stains.
Any advice would be greatly appreciated. (see photos attached)
Unexposed to vertical rainfall? What about blown in inclement weather?
The porch landing is sloped away from the building. There should be weep holes every so many feet and scuppers to lead bulk water out.
Are these low spots where moisture is the last to evaporate?
when did the stains start appearing? if it was less than 7 or 8 years ago i would imagine it is not due to penetrating any vapor barrier or you would have seen it sooner. just out of curiosity, did you contact the company that drilled the holes and ask them anything about them? i would start there if it were my home.
The porch is covered by a roof that extends from the house. It is not exposed to the elements, but could be coming from underneath.
I don’t see any weep holes. What are scuppers? The porch is flat with no low spots.
I’ve attached a few more photos of my porch.
It started within the first 6 months of having it done. I did have them out once, but at that time, it was just a few small spots and they just blew it off. I regret ever having it done now that I know what I know. I just want to get them filled. Maybe bondo or spray foam or should I stick with a mortar mix (powdered or in a caulk tube).
The holes they drilled were only corked and thinly patched over with the concrete dust from drilling. Some of the holes opened up and that’s when I noticed that they only covered up the top. I suspect that’s why water is coming up. If you see in the pictures, it’s only around the areas that were drilled. I’m thinking the holes need to be filled with something that’s waterproof. Also, would it be okay to partially fill the holes with sand to fill the bottom of the void where I may not be able to reach with concrete/mortar patch.
Please post a photo of water from the drilled holes.
I see holes patched/sealed only.
It is quite common to seal on the top only. A filler is applied first so the top seal does not sink in when curing.
I mistook the masonry for a guardrail. If there was a masonry guardrail weep holes and scuppers would be installed.
Remember, rain can be blown onto the porch’s concrete landing.
I suspect the stained concrete is due to water being wicked into the concrete and slower evaporation at the stained areas.
Hydrostatic pressure, also known as rest fluid pressure, refers to the pressure exerted by a fluid at rest due to the column of that fluid above a specific point in it. The concrete slab is above grade.
Understood. It’s just odd that it appears just where the holes were drilled.
So any thoughts on what I can use to fill those holes and make them water tight?
Hi Marc - if you hit those spots with a hair dryer, do they disappear, or are they always darker than the surrounding concrete? You can drill out the patches and replace the patches with new patches of your choice of patching material (which may or may not better match the surrounding concrete), but I think the others here are trying to get closer to a description of the actual problem. Like others have said, the porch surface is above grade - hard to see how water would want to push up into those patches.
Dig a hole in the soil a few inches deeper than the slab sits in the ground. Cover the hole from potential rainwater or sprinklers entering it.
Does the hole collect water? Assuming that it does, it is from rising ground water.
What level is the ground water at in your area? How consistent is that height/depth?
Does it fluctuate with light/heavy rains? So many questions that can’t be answered without being on site.
I will try the hair dryer and report back.
At one time, I thought they could have hit a DWV pipe, but I had those located and inspected with a camera and found no intrusions.
