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Nightcrawler 09-18-2009 05:25 PM

Basement Concrete Block Mortar Seepage Advice
I've got a 1960 cape cod with concrete block basement. I've been working toward seepage mitigation and I'm looking to get some advice based on the images below. These are two different walls in my basement that are having the seepage issue.

As you can see, most of it is seepage through the mortar joints. There is also some seeping in between the wall and floor.

I know starting with the outside source of water is always best and I've been working on that for months and am about done outside with the typical things including gutters, sending output 10 feet away, moderate grading work (still could use some improvement.)sealing concrete by porch/sidewalk etc. It's improved, but still under very heavy rain, the problem persists. So, that brings me to the real questions I have to day about the mortar joints.

The mortar joints are old and most have hairline cracks and/or other minor decay.

1. If I have these mortar joints touched up, would that eliminate any of the seepage? Or will it seep through the block anyway?

2. It seems as if the floor meets the wall at a mortar joint as well. If I get somebody to chisel a bit and put a thin layer of hydraulic cement there or something, would that prevent seepage at that point?

What I'm trying to find out is if it's worth trying to get the mortar joints fixed up or it's futile and that will not do anything for the seepage. Besides those two walls, I have other small areas (a block or two here and there) that seep. In most all cases, it just slowly seeps out the mortar joints and eventually runs down the wall. I even see some seepage along the mortar in the corner of the basement between two adjacent walls. It only happens under heavy downpours (bad summer storms, fall nor'easters) and it's never really enough to make puddles on the floor, just run marks down the wall and a little bit on the floor in the worst areas as you can see from the images.

Any advice or guidance would be appreciated. I'm not interested in spending the money on a full professional solutions like digging up the foundation or anything.

stadry 09-19-2009 05:10 AM

if you're a bsmt wtrproofing contractor, block walls're manna from Heaven :yes: its been said ea lf of mortar jnt's got 100s of pin holes allowing vapor & soil acids to attack cement's lime causing efflorescence ( calcium carbonate salts ),,, excavation, cleaning the walls to the footers, & troweling on waterproofing coating will work but its major work even tho it won't require much brain power,,, short answers: 1, no; 2, no.

problem started outside ( positive side ) - building code only requires a 3mil dampproofing coating applied by either brush, roller, or spray,,, this is a non-elastic layer & is often damaged by backfilling,,, sincer wtr runs downhill, seeks its own level, takes the path of least resistance, & rushes to fill a void ( try making a hole in your tub full of wtr ), any solution that doesn't address these rules is bound to fail no matter whether done by pro, diy'er, OR angels from above :laughing:

sorry you're not interested in the right approach but anything else is a waste of $,,, failing that, wait til its time to sell the house then give it a coat of drylock ' type products,,, won't work, either, BUT you can honestly say there was a problem & you've address'd it,,, very few home inspectors'll know the difference so you'll probably pass :mad: & avoid legal action.

inspected a home yesterday that has water intrusion at the floor/wall ( cove ) junction,,, he can probably resolve it by injecting hydrophyllic polyurethane grout but his 1st step's regrading the exterior to provide positive drainage [ a given & necessary no matter what ],,, if it works, he's only out $750 compared to ext excavation & coating @ $15K & $3.5K for injection work,,, eventually yrs down the road, he'll have to do more work but its my opinion this method'll work well for 3 - 5 yrs.

Knucklez 09-19-2009 04:11 PM

4 Attachment(s)
not to rain on your parade..:boat:

but excavating exterior walls for waterproofing is NOT a DIY job. even though it is 90% labour.. you still have to know how to dig a hole safely and with bracing because of cave in risk. the excavation is narrow and deeper than you are tall.. not something you want to do without pro help.


stadry 09-20-2009 04:50 AM

knuck's right, of course, however any h/o|diy-er can do whatever he wants,,, if you send employees into the hole, THEN you've got specific safety concerns including soils analysis, shoring, & retrieval.

Nightcrawler 09-22-2009 05:13 PM

So, in other words, the mortar joints don't look bad and touching up the mortar won't help at all? I mentioned above, I wasn't interested in a full excavation professional solution. I don't have the money for that and the seepage isn't that bad. I have been trying everything I can on the outside of the house.

stadry 09-22-2009 07:20 PM

i said my piece,,, we do this work for a living & must guarantee our work,,, you don't have that concern & can do it more than once OR as many times as needed,,, i can't afford that approach !

ps - the seepage WILL get worse,,, trust me on that !

jomama45 09-22-2009 08:57 PM

I also do some foundation repair on block basements for a living, but generally refrain from commenting on these posts for a number of reasons:

- Every foundation is contructed differently depending on age, practices, area, etc....
- I have very little interest in the repairs, not exactly "artwork".
- There is no easy, long term way to repair from the inside, which is usually the path in question.
- It would take me days to put into writing what it has taken me many years to learn on the job.
- Generally, IRC makes the points I would try to convey anyway, in a much more "interesting" way though!

I will give you a little direction though. Regardless of IRC's opinion of block foundation walls, they do have one added benefit when it comes to leaks. They have a hollow core, or secondary line of defense, that should be utilized properly to avoid leaks. Start searching the forum (& the internet) for diagrams on the proper draintile system, noting how the interior & exterior tile, bleeders & sump crock are designed to work together. You need an understandign on how the system works as a whole to get any idea on how to curb leaks. We often install "retro-fit" bleeders from the inside of basements to control the water that reaches the INSIDE of the block.

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