Basement Waterproofing

Matty1stop

I've got a basement I'm trying to waterproof. The house is south of Boston, MA. Cape style house built in 1960. Its got a B-dry french drain along the back in the foundation emptying into a sump pump that drains about 20 feet from the foundation and a stand alone sump pump in a well in the front of the house that empties onto the driveway. They have gotten water 3 times in the last 7 years under extreme rain or thaw conditions. Never more than an inch or so.

The ceilings are prettly low so they don't want a sub floor if they can avoid it.

I was looking at thoroseal or sanitred but don't have any experience with either of them.

I would appreciate any suggestions that anyone has.
Thanks,
Matt

concretemasonry

Of the coating my favorite is properly applied Thoroseal (two coats with an additive - Acryl 60).

The house has basic water problems with a cheap patch-job approach that has proven to not be adequate.

Remember - a surface coating is only a band-aid and will not work unless other factors are correct.

The house should have gutters, 10' downspout extension and positve drainage away from the house.

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Dick

Engineer, designer and consultant recently active domestically and internationally on construction and design in about 35 countries.

Matty1stop

Is there another method that you would recommend for this situation?

concretemasonry

It should have been buit with drain tile on all four walls (inside outside or both).

If you want a dry basement, could install drain tile in addition to sealing the walls and sealing the floor/wall joint (open the joint and pack it with hydraulic cement).

If you just apply a coating, there is no guarantee the basement will be dry, but it certainly will not be as wet as it was.

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Dick

Engineer, designer and consultant recently active domestically and internationally on construction and design in about 35 countries.

denick

Mat,

You don't say what the foundation is built of?

What shape the walls are in?

Is there anything on the walls already?

What shape the floor is in?

You said they have gotten water 3 times but is the basement damp or wet?

As concrete said, what are the conditions around the outside of the house?

A picture of the layout and conditions would go a long way in helping answer you?

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Nick

"Every day I remind myself that my inner and outer life are based on the labors of other men, living and dead, and that I must exert myself in order to give in the same measure as I have received and am still receiving" Albert Einstein

DamionR

Matty,

I work i nthe waterproofing industry. If a B-Dr system was installed - it comes with a warranty. Contact B-Dry (or the homeowner) to find who instaleld the product, and get them out there for a service call.

Typically I do not recommend any type of waterproofing paint to apply to the walls. All that will is trap the water behind (or worse if it's a block wall, inside) the wall.. which will break down eventually... can lead to structural wall repairs, etc.

But, since that's not your concern... either or will work as a temporary band-aid.

BreyerConstruct

Damion,

If I can quickly piggy-back this thread:

If a concrete basement on a new house is constantly getting damp walls, shows efflorescence, but appears to have proper exterior drainage.. what do you do?

Sorry to butt in!

~Matt

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DamionR

Hey Matt,

If this is the case... the outside drainage is most likely either:

• Installed improperly
• Clogged with Silt/settiment
• Crushed during the backfill process

I'd be willing to vet that if you drileld a small hole into one of the blocks near the bottom (where you see the efflorescence), water would pour out.

I'd recommend an interior drain tile system. You can do something like what is done on the outside, and run it to a sump pump. I worked with the basement systems line of products (www.basementsystems.com). Pip sits on top of the footer instead of besdie it (in the mud where it can clog). Plus installatino is typicalyl easier. Obviously, you have to be a licenced installer - so you'd have to get someone to do it.

Matty1stop

The basement is poured concrete. It could use a dehumidifier but it isn't damp or wet. The walls look OK but some of them had panelling installed as it was a finished basement with wall to wall carpet before the water came. The carpet is now removed but there is some old tile on most of the floor, but I believe the water is coming from the floor not the walls.

There are normal downspouts (no extensions) around the foundation. I can take some pictures and post them if you think that will help.

When they contracted b-dry they sent a salesman out who only gave them an estimate for finishing the perimeter.

Thanks for the help,

Matt

denick

Matty,

Pictures could help a lot.

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Nick

"Every day I remind myself that my inner and outer life are based on the labors of other men, living and dead, and that I must exert myself in order to give in the same measure as I have received and am still receiving" Albert Einstein

denick

Brey,

you say "damp walls" is that all they ever get?

How new is the new house?

Where in the country are you? What is your climate like? What is the soil like?

__________________
Nick

"Every day I remind myself that my inner and outer life are based on the labors of other men, living and dead, and that I must exert myself in order to give in the same measure as I have received and am still receiving" Albert Einstein

concretemasonry

Normal downspouts are as bad as or worse than no gutters. They just collect water and dump it close to the house where the "junk" backfill was dumped.

Doing one wall of a basement is not much better than doing nothing. It only changes where the water will come in.

The excavator digs a hole for a swimming pool. The builder hires a mason contractor to build a basement in it. He then builds a pretty house to sell. The buyer does not relize he is living is an inside-out swimming pool.

You have to keep as much water out of the excavation area that is about 5-10 feet beyond the walls plus the excavators access ramp that wil funnel water into the hole for years since good backfill and compaction is rare.

Downspout extensions (10') help get the roof water away from the house. This is cheap and easy to do. After that, drain tile (inside or outside the footing) is the best way to reduce the hydrostatic pressure on the walls AND under the slab.

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Dick

Engineer, designer and consultant recently active domestically and internationally on construction and design in about 35 countries.

DamionR

Downspouts are not the culprit here. Typically, you would see the damp spots start at the top of the wall and spread out almost liek a Christmas tree.

There are two possible culprits here.

The area you are mentioning where the footer, floor, and wall come together - the cove area. It's a natural seam where water can come in.

The second culprit is hydrostatic pressure. Water is self leveling. Here's some good info on the basement systems website - http://www.basementsystems.com/learn...owl_effect.php

An interior system is your best bet.

You made one statement that confuses me. you said there is a B-Dry system against one wall.. but also said the sales rep only quoted a full perimeter option. Which one?

Matty1stop

DamionR,

Sorry for the confusion. The B-dry system is against the back wall. I think the previous owners had trouble with water coming in the bulkhead area.

The B-Dry salesman was writing up an estimate to have the rest of the perimeter done.

DamionR

I see. A system along those lines would be the best solution. You have water problems from either hydrostatic pressure (coming up through the floor).... and/or water comign in at the cove area. The B-Dry systems apparently works. Basement Systems has a great product I liekd called Waterguard. You can call install an interior draintile system yourself if that is somethign you are capable of doing.

concretemasonry

Matt -

It sounds like you are not planning on finishing the basement, but just want to waterproof it without full-fledged construction. This involves several steps that are not major projects:

1. Make sure you have done everything out side your house, including 10' extensions, to get the surface water away. If the exposed extensions are annoying, you can locate pop-up bubblers away from the house. I have had great luck with mine.

2. Open the joint (grinder or chisel) between the floor and the wall. This gap occurs when the concrete shrinks and your concrete finished shrinking years ago. Force hyraulic cement (a generic product) into the joint and allow it to expand and set. The surface does not have to be dry and the material expands and sets rather quickly. It is has been the standard material used for plugging cracks in concrete for many years.

3. Coat the walls with one or two coats of Thoroseal. Thoroseal has been a standard material used for over 50 years in the waterproofing, repair and restoration of concrete structures. Is has a long history of performance on residential, commercial, industrial and civil (dams, etc.). It is not a paint!. It is available in bags and is mixed with water following the diections and timing carefully. It is applied to a damp wall to insure a good bond. An additive (Acryl 60) can be added for increased properties.

It is obvious the B-Dry system on one wall only moved the point of leakage since it really does not substantially reduce the hydrostatic pressure on the walls and slab.

If you really want a dry basement for finishing, you should install drain tile with a filter fabric and gravel/sand at or below the bottom of the footing. You can do it yourself, but it is hard, messy work. I did it by renting a masonry saw for a few hours and did a lot of work on a few weekends. If you really want to get rid of the water you have to go deep and not go with a partial system like D-Dry or Waterguard that does not draw water away from the exterior of the wall.

__________________
Dick

Engineer, designer and consultant recently active domestically and internationally on construction and design in about 35 countries.

woodmagman

I live an a climate that has extreme changes in weather (Alberta). The freeze thaw cycle is the most common reason for cracks to form in foundations, not saying hydrostaic presure is not reason. We have gone through a learning curve for the past 15 years when comes to repairing cracks. We started with expanding grout, then low pressure epoxy injections now urethane foam injections. The foam injections are more flexible then the two others and will flex with the slight foundation movement. The urethane reacts with moisture and expands in the the crack. The best is still a exterior repair with digging and installation of a membrane.

tacman

I am always amazed at how much people will spend at water proofing their basement when 95% of time they just had proper working gutters and downspouts along with positive landscape grading they would be fine. Do you find the same?

DamionR

nope

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Tom R

Yes, definitely yes, - - and from an 'unbiased' opinion here.

I mean, c'mon now, Damion . . .

I've been gettin' water in my basement since I moved in.

Last summer I finally got around to runnin' the downspouts into underground drain pipes fed away to daylight.

Voila, - - nary a single 'drop' since.

Oh yeah, - - forgot too mention, - - the wifey had called a 'basement waterproofing contractor'.

$18,000!!

Yuh, - - OK . . .