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WATER ENTRY in BUILDINGS
AGE of MOLD, HOW OLD
BASEMENT CEILING VAPOR BARRIER
BASEMENT MOLD WATER IMPACT
BRICK WALL DRAINAGE WEEP HOLES
BUCKLED FOUNDATIONS due to INSULATION?
BUILDING DAMAGE ASSESSMENT & REPAIR
CONDENSATION on WINDOWS & SKYLIGHTS
DEW POINT TABLE - CONDENSATION POINT GUIDE
EFFLORESCENCE SALTS & WHITE DEPOSITS
FLOOD DAMAGE ASSESSMENT, SAFETY & CLEANUP
FLOOD DAMAGED FOUNDATIONS
FLOOD VENTS & FLOOD PORTS
FLOODS in BUILDINGS, MOLD PREVENTION
FLOOR DAMAGE DIAGNOSIS
FOOTING & FOUNDATION DRAINS
FOUNDATION BULGE or LEAN MEASUREMENTS
FOUNDATION CRACKS & DAMAGE GUIDE
FREEZE-PROOF A BUILDING
FROST HEAVES, FOUNDATION, SLAB
GOPHER HOLE DAMAGE
HUMIDITY LEVEL TARGET
ROOF ICE DAM LEAKS
MOISTURE CONTROL in BUILDINGS
MOLD INFORMATION CENTER
NOISE / SOUND DIAGNOSIS & CURE
ODORS GASES SMELLS, DIAGNOSIS & CURE
SEWAGE BACKUP, WHAT TO DO
SEWAGE BACKUP TEST & CLEANUP
SEWAGE BACKUP PREVENTION
SEWAGE PUMP CLOG DAMAGE
STAIN DIAGNOSIS on BUILDING EXTERIORS
STAIN DIAGNOSIS on BUILDING INTERIORS
SWEATING (CONDENSATION) on PIPES, TANKS
TOILETS, INSPECT, INSTALL, REPAIR
TRAPS on PLUMBING FIXTURES
VAPOR BARRIERS & CONDENSATION in BUILDINGS
VENTILATION in BUILDINGS
WATER ENTRY in BUILDINGS
WINTERIZE A BUILDING
Foundation drainage: this article discusses building foundation drainage: footing drains, used to prevent foundation leaks and building water entry. This article series discusses types of drainage system s, including foundation drains or "french drains" for preventing wet basements and crawl spaces.
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Our page top drawing of types of indoor foundation and basement drainage systems is provided courtesy of Carson Dunlop Associates.
[Click to enlarge any image]
Definitions of a Footing Drain, French Drain, & Perimeter Drain?
A footing drain, that is an exterior foundation drainage system placed outside the foundation wall near the wall footing, at the level we show, covered with gravel, and if the footing drain going to do anything, it is piped to daylight or to a catch basin that is in turn pumped to daylight or to a storm drain.
Well plenty of people do call interior foundation drains or perimeter drains a "french drain". We don't.
A "French Drain" is an outdoor buried drain line constructed to carry water away from the building, typically to a drywell or catch basin. Our sketch shows how we remove water from roof runoff that pours down a downspout.
Details about French Drains are at FRENCH DRAINS for DOWNSPOUTS
So what is the difference between a french drain, a footing drain, and a perimeter drain. A French drain is shown above, and a footing drain is shown in our two sketches below.
A perimeter drain is an indoor drain cut into the floor around the perimeter of a basement or crawl space to intercept and remove water from the building interior. We illustrate perimeter drains above.
Details about interior perimeter drain systems are at PERIMETER DRAIN SYSTEMS
Building Footing Drain Details
Find the end of the footing drain system that used to drain to daylight (see our photo below). The foundation drain system may have become buried with mud or covered by backfill. Clear any blockage at the end of the footing drain extension, open and check the end for water flow in wet weather.
Clogged Footing Drains
Even if foundation drainage was properly installed when a building was constructed, the system may no longer be working. Over time fine soil particles can enter and clog the foundation drainage system.
If you know that a foundation drain system was installed - perhaps you can find the end of it as we illustrate above - and if the building foundation is leaking water from low on the foundation walls, and if little or no water is coming out of the end of the footing drain in wet weather, it's a good bet that the drain system has clogged.
Our photo (below left) shows the footing drain that was excavated and removed at the home of a client whose house suffered recurrent flooding. The old footing drain was totally impacted with mud.
The photo at above right shows the ends of three new footing drains that were installed and carried to daylight. We remained a little nervous about just what the builder used for backfill - notice that silty mud coming out of the new drains? They may not have a long life.
Foundation Drainage Backfill Details to Prevent Basement Water Leaks
Overloaded Footing Drains
We explain at GUTTERS & DOWNSPOUTS that it's a bad idea to connect the roof drainage system to the building footing drains. The added water volume may overload the drain system leading to foundation leaks.
And worse, when later in the life of the building the foundation drains clog, we suddenly begin directing 100% of the roof runoff into a lake of water trapped around the building foundation - virtually guaranteeing that the basement floods.
Our photos (below) show a home whose roof drainage system passed through the crawl space wall, across to the other end of the building, exited the crawl space to go back outside where it dove down into the building footing drain system. The result was a constant wet finished basement.
Notice in our second photo (below right) that a clue telling us the whole drainage system was clogged and backing up was that during rain water leaked out of the tee at the top of the vertical drain line that was connected to the footing drains.
At a recently constructed home we determined that the roof gutter system was connected to the foundation drains, and warned the buyer about the chances of basement flooding. The home was ten years old, and the basement, by every inside inspection indication, was "dry".
But two years later, following a period of heavy rain the client called to exclaim "Geez, our basement is full of water!" IT was like throwing a switch. The footing drain outlet clogged and the basement just filled right up.
Here we include solar energy, solar heating, solar hot water, and related building energy efficiency improvement articles reprinted/adapted/excerpted with permission from Solar Age Magazine - editor Steven Bliss.
Continue reading at BASEMENT WATERPROOFING
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