# Basement Waterproofing - Parging



## Yakman256 (Mar 25, 2014)

Hey All… I just found this forum and think it’s great. Normally, I deal with Site work but I’m a little short on masonry knowledge so I thought I would post here.

I’m planning on tackling a basement waterproofing project for my home outside Philadelphia, PA. The Phase 1 portion of the plan is to excavate around the perimeter of the dwelling, apply a layer of parging to the exterior cinder block wall and apply an asphalt based product before backfilling with #1 stone. I should also note that I will be adding a foundation drain to a sump so water will be collected and pumped to an appropriate outlet. The exterior basement wall is bare and does not have any paint or asphalt coating applied. 

Is there a pre mixed product that I can use for the parging?


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## stadry (Jun 20, 2009)

1st make whatever necessary masonary repairs are needed,,, THEN waterproof - we use hlm5000 protected by hdpe waffleboard OR 19mm pond liner,,, 

parging isn't necessary OR required,,, should've had a 3mil worthless dampproofing coating applied when it was built,,, perhaps the builder forgot ?


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## eharri3 (Jul 31, 2013)

Depending on how old the home is it may not have gotten that sort of treatment at construction.

I have gotten estimates from two different water proofing companies before when I had minor issues with water in my basement. Neither mentioned parging. Both mentioned patching the wall with hydraulic cement, then going over the problem section with asphalt, then doing a membrane on top of the asphalt. Both said that they hate having to re-do jobs like mine that involve hand digging in confined spaces, so they don't use procedures that lead to 'call-backs.' 

Parging is a cosmetic thing to create an even surface over concrete masonry walls to smooth over minor imperfections and prep for paint. With walls like yours it can be a good first step to create a more uniform surface for the asphalt material and other layers of water proofing to adhere to, but it is not considered water proofing in and of itself. At best it can in above-ground situations be a 'sacrificial layer' that protects the material underneath.


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## Yakman256 (Mar 25, 2014)

The cinder block appears to be pretty course with some very poorly done joints. My hope was to patch any areas where I thought the mortar was lacking and spread more of the same material over wall prior to adding the asphalt coating. Its my understanding that there are microbes in the soil that will actually eat the asphalt coating so I was looking for an additional layer of protection. 

I've been reading a lot about different types of mortar. Some say mix in lime to mortar, some say use type 's' mortar some say use white Portland cement. 

I'm really familiar with the Pond liner. I used to spec that material when I designed manure storage pits for farms. Very expensive and not a DIY product although I think the platon Matting would be appropriate and similar in cost to a parge coat.

Thanks for your replies.


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## stadry (Jun 20, 2009)

there's no parge coating that will adhere to hlm5000 & asphalt products are clearly the wrong material as they're not elastomeric,,, most waterproofing co's aren't masonary/concrete repair specialists,,, 'sides which, most 'inspectors' are just salesmen repeating the company 'pitch'

microbes need food - most masonary problems are caused by acid in the soil attacking lime ( cement =lime - iron - silica - aluminum )

19mm pond liner's probably tough enough to withstand the rigors of backfill w/o tearing,,, waffleboard's certainly satisfactory but we find liner faster & easier - about the same $ considering time & labor


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## Yakman256 (Mar 25, 2014)

I got the idea of parging from a "standard construction detail" I found in an old manual in the office. I'm glad I posted my question here. As I said I'm a little over my head on the masonry world. I called one of one our construction suppliers and they said they carry the dimpled membrane (superseal or Platon equal) 

Two more Questions: 

1. How do I fasten the membrane to the block wall? Can I just Use Masonry nails and a hammer? I know the dimpled matting comes with fasters but I don't want to use the wrong fastening product.

2. What is an hlm5000 product?


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## landfillwizard (Feb 21, 2014)

How tall is the wall you will be working on? Are you going to hand dig or have a contractor excavate next to the wall. If the wall is taller than 4' the walls of the excavation will need to be re-enforced or terraced.


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## stadry (Jun 20, 2009)

i'm old, too, but that's no reason we do it our way - I like belt AND suspenders approach :yes:

their equals are fine - just overlap the top 1 over the btm piece :thumbsup:

hlm5000 is sonneborn-basf's product {http://www.dhcsupplies.com/store/p/2370-HLM-5000-Liquid-Elastomeric-Waterproofing-Roller-Grade.html } meadows also has an equal [ no $ interest ]

masonary nails w/washers & an aluminum termination strip above it - then seal the termination strip w/100% silicone sealant


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## Yakman256 (Mar 25, 2014)

The excavation will be up to 5'. I have to hand dig one side of the house to a depth of 3.5' because there is a roof overhang that I cant get equipment under. The rest I have a contractor that we work with at the office that will dig the rest to a depth of 5' These areas I'll have trench protection. Like I said before I have experience with site work just not masonry.


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## landfillwizard (Feb 21, 2014)

When waterproofed the outside of my house foundation I used an asphalt coating over the blocks. I then applied a heavy duty polyethylene plastic over the asphalt while it was still tacky. This held the the plastic in place while I backfilled. I used washed #1 and #2 stone mix up to 1' below the top of ground. This stone covered the footer drain. I placed a geotextile fabric to cover the stone and placed top soil above the fabric. 

I backfilled the excavation slowly and did not have any problem with blocks cracking. It has been 25 years and I have not had any water coming through the blocks. Of course I lost the house in a divorce but the wall is still water tight. I would pressure wash the blocks and let them dry before I applied the asphalt.

This worked for me so just thought it might help you!


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## Yakman256 (Mar 25, 2014)

Itsreallyconc - How much coverage will you get out of a 5 gal pail of HLM5000? 

Landfill - that's exactly what I wanted to do except I was considering applying a parge coat to the outside block before adding a coating but I'm finding it may be unnecessary. I'm still waffling on the coating to put on the exterior wall. With stone filled to nearly the top of trench and an underdrain, the coating is really only a secondary defense against water intrusion and really is only useful if/when the stone and/or the underdrain is chocked with sediment which will definitely happen over time. Since I wouldn't put a lifetime guarantee on anything the question really is...How Long will the coating last?


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## jomama45 (Nov 13, 2008)

Yakman256 said:


> The cinder block appears to be pretty course with some very poorly done joints. My hope was to patch any areas where I thought the mortar was lacking and spread more of the same material over wall prior to adding the asphalt coating. Its my understanding that there are microbes in the soil that will actually eat the asphalt coating so I was looking for an additional layer of protection.
> 
> I've been reading a lot about different types of mortar. Some say mix in lime to mortar, some say use type 's' mortar some say use white Portland cement.


Type M is actually the best choice for below-grade structural, which is what you're dealing with. The extra Portland holds up better to the constant moisture.

There's a number of different forms of dimple board available. One other benefit of using them is that they protect the damproof coating from damage during backfill.

This company has decent products and an even better website with good illustrations:

http://www.mtidry.com/basement/


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## stadry (Jun 20, 2009)

we plan on 5gal yielding 250sf,,, uncertain why you'd want to parge AND waterproof - parging's not necessary imo,,, stone & the toe drain might seem enough but they ain't,,, however it is your house :whistling2:

we've only used it for 15yrs ( 1 form or another so no idea how long it lasts ) lessee, i'm 72 + 15 = 87 :thumbup: nah, i ain't worried :no:


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