foundation waterproofing

Other than burning down, probably the worst thing that can happen to a residential structure is a foundation problem. The foundation is literally what the house is built on, what keeps the building where it was built, transferring the dead loads and the live loads into the ground.
The source of the vast majority of foundation problems is water. Wet soil beneath a foundation can swell or lose strength.
Shop for foundation waterproofing products & vapor barriers designed to protect your foundation.
And that’s only the first reason to keep the foundation dry.

Then there’s the little problem of wet damp basements and crawl spaces that can breed mold and make below-ground interior spaces generally unpleasant. The problem is that typical concrete is not waterproof. Although uncracked (and what concrete is uncracked?) it will typically keep out liquid water, water vapor can still penetrate quite easily.

Keeping water drained away from concrete foundations and preventing it from moving through the concrete are essential to a successful structure.

Accomplishing our goal, then, of draining any water away and ensuring a dry interior space below grade can be relatively simple or fairly involved depending on geographic location, climate, topography, soil/water table conditions, and depth of the foundation. There are three components of any system designed to keep water out. These are, from the bottom up:

Drains to move water away from the bottom of the foundation waterproofing
Wall treatment to prevent moisture from moving through the wall and to route water down to the drains
Ground surface treatment adjacent to the building to direct surface water away
And remember that since this will mostly be underground when the building is complete, doing it right the first time is critical, because coming back to fix it is an expensive undertaking.

A leaky foundation in a residential building can damage finishes and furnishings, even the structure itself. In a commercial building, water can ruin expensive equipment and disrupt vital work. It all adds up to lost money, wasted time, upset customers and sometimes litigation.

HOW TO WATERPROOF A FOUNDATION

Scheduling and Planning For Concrete Waterproofing
Allow considerable float time for waterproofing. If you’re using a waterproofing subcontractor, recognize that good waterproofers can be in high demand during the busy season. Rain can also delay foundation waterproofing work.
Plan the layout of waterproofing well ahead of time. The plan elevations will likely show the finish grade line on the foundation walls, but these lines should be confirmed with the architect, if necessary.

You don’t want black, gooey waterproofing showing above grade. Watch for changes in the level of grade. A line of waterproofing descending at a diagonal from one level to another won’t work if the architect has decided to handle the change with a retaining wall.

Construction Tips

Ideally, you should mark layout lines with a crayon or chalk line, especially on a complex foundation with varying grade. On a simple foundation, it might be safe to just instruct the foundation waterproofing to keep his work so many inches from the top of the foundation. I like to see waterproofing as close to finish grade as possible, but no lower than 6 inches in any case. Don’t leave form-tie holes that are below grade unprotected.

Work out ahead of time what you’re going to do at basement windows and bulkheads, porch foundations, and intersecting walls that don’t have to be waterproofed.

When deciding what walls get waterproofed, follow this basic rule: Waterproof any foundation wall that has earth on one side and usable space on the other, including crawl spaces. Extend waterproofing at least 12 inches onto intersecting walls that don’t have to be waterproofed. You might want to continue the waterproofing on other walls if it’s a very wet site. Under extreme conditions, water has been known to travel through the keyway along the footing and into occupied space. Consult with the architect if you have any doubts.

Check the waterproofing manufacturers literature for temperature limitations. You’re probably okay applying waterproofing on a cold day if you’re working with a solvent-based material. But watch out if your material is water-based. The lower limit for some products is 40F.

What is an Exterior 

foundation waterproofing

Membrane

Water coming over the top of the foundation waterproofing, through a masonry foundation wall (brick, stone or concrete block), through a porous concrete foundation or if your basement is nicely finished are all reasons an exterior waterproofing membrane may be the best solution to keep your basement dry as crack injections are not applicable in these cases.

An exterior waterproofing membrane is a coating that is applied to the exterior of the foundation waterproofing. It is intended to stop water before it has a chance to pass over or through the foundation wall. This eliminates the damage the water can cause to the foundation wall itself as well as other components of the building or personal belongings if your basement or crawlspace is finished or used for storage.

How is an Exterior Waterproofingled Membrane Instal

Installation of an exterior waterproofing membrane is relatively straightforward once the problem is properly diagnosed. If the issue is water coming over the top of the foundation, minimal excavation is required, the membrane only needs to be applied to six inches below the top of the foundation.

If the problem is water passing through a masonry foundation wall or porous concrete wall, full excavation to the footing depth is typically required.
The process to install an exterior foundation waterproofing membrane includes:

Removal of any obstructions such as decks, pavers, plantings, sidewalks, patios and driveways.

Excavating the foundation wall to below the problem area.

Cleaning the foundation wall and repairing any obvious defects.

Installing the waterproofing membrane, we prefer a thick liquid, trowel applied version. This material needs to cure which, depending on weather can take a few hours or a few days.

Installing a drainage board which acts as a secondary waterproofing barrier but more importantly protects the exterior waterproofing membrane from damage when the excavation is backfilled.

In the case of severely saturated soil outside a foundation wall, an exterior drain tile system would be installed at the depth of the footing to carry the additional water away to a sump pump system or to daylight via gravity.

The trench is backfilled with the excavated material in compacted twelve-inch lifts. Once this is completed, final landscaping can be completed. Minor settlement of the excavation is to be expected.

If you have water coming over the top of your foundation or through your foundation walls, contact Ariankhak iranian for a free consultation. Our staff can help determine where the water is coming from and which exterior waterproofing membrane application is right for your situation.