How to remediate water problems in your home
Recovering from the flood:
Over my extensive career in east coast homebuilding, I have learned many techniques to remediate persistent or cyclical water issues.
- Water flow has memory. When water creates new channels around the foundation, it will continue to follow these pathways unless redirected. The natural resistance of the foundation form impedes the flow from uphill sources, underground streams, and supersaturated soils.
- Pitched roofs direct rainwater to their edges filling gutters and leaders. The resulting concentrated flow is dumped at the foundation edge to be absorbed by the landscape plantings or to run away on grade.
- Lots in low-lying or flood-prone areas are at the bottom of natural drainage flow. Water does not flow uphill unless pumped there.
- The type of soil determines the site’s ability to absorb a temporary deluge. Sandy soil drains well; clay and sedimentary/boggy soils do not.
- Whether or not the original construction was done with foundation drains around the perimeter at the footing level determines whether or not water at the lowest level of the foundation can move away from a basement or crawl space. Typically on hilly sites, this potential water is drained downhill to daylight or if necessary into a drywell construction either fabricated on site or prefabricated.
- In general it is obvious that water and houses do not mix except in plumbing systems. Keeping water out of the building should be an ongoing priority from day one of construction. When site clearing, remember that the root structure and accumulated natural litter were nature’s way of controlling and directing water.
- Existing streams and springs should be respected and intentionally redirected into storm drains taking the water flow away from the upcoming excavation.
- Water flow such as underground streams when disturbed must be actively pumped with a float-activated pump chamber seated below the basement or crawl space floor level – during and after foundation pouring.
- Excavations during the dry season often do not represent the true water conditions of the site. Water movement as it percolates through the site strata takes time and is part of the natural ecology. The excavation pit creates a sump for the natural flow to settle in. This is why foundation drains are critical; they can be installed later by jack hammering the slab at the interior perimeter and draining them into a new pump chamber but this is time-consuming and costly.
Big water events as continual rain for days or torrential downpours create flooding as the water accumulates downhill. Preventing catastrophic damage from uphill conditions often requires site drainage in the following forms:
- Swales, which are cuts in the landscape to catch water and slow or redirect it away from the structure
- Berms or walls to slow down and redirect the flow
- French drains, which are perforated PVC pipe in a gravel trough covered by landscape fabric. These drains go to daylight on either or both sides of the dwelling
- Sumps with catch basins situated in patio constructions specifically designed to focus the water into the basin and channel it through buried pipe to daylight. In the case of a courtyard where the water of roofs and patios cannot escape, this is essential.
Master landscape plans in wet areas or flood zones can utilize any or all of the above to keep water out of the house.
If the basement of the building has minor or persistently light water incursion, installing a permanent sump pump is relatively easy and cost effective. Many systems operate on a battery backup standby or can be set up with a dedicated GFI circuit. If you have a generator, the circuit can be set to kick on when the power fails.
I have opened many slabs where the water table is just below the slab base. This type of pooling creates a high moisture condition in the basement or crawl space, perfect for the development of mold. After pumping out this water the entire site begins to dry out and you now have a way to keep the water out.
After remediation and dewatering, the basement slab and walls, if accessible can be sealed with any number of different sealants. The Drylok System works well and has proven to be very effective and long lasting.
Dumping rainwater at the edge of a foundation is asking for trouble. Creating a shoal depth PVC drain system (where the leaders are connected) to take this water to daylight or a drywell is an essential component in your water control system. Often this alone prevents water from entering a building’s foundation.
Older homes sitting on block or stone foundations need to have any cracks filled or a total pointing of the joints between the stones. After complete drying, these foundations can be sealed with a heavy coat of waterproofing. Sometimes a coat of stucco is required in very rough conditions before sealing.
Water conditions are unique to each home. Understanding what is INVISIBLE to the eye requires the patient approach of viewing the conditions over time. In many cases, it requires several or all the above remedies. There is no substitute for years of experience in water remediation to solve problems of water incursion in the home.
If I can be of service regarding water concerns, please call me at 303.916.0008.
I will visit your site and freely share my observations and thoughts on your situation.
Free WATER REMEDIATION SURVEY through October 22, 2013.