How To Find the Best Waterproofing in Marin County CA
Water in the basement (especially a flooded basement), a flooded crawlspace, the need for sump pumps or sealing the basement against water, roof leaks and deck leaks are all issues of waterproofing in Marin County. Waterproofing contractors in San Rafael CA provide water sealant services, leak detection and leak prevention through the use of water repellents, wall coatings, waterproof membranes, and more.
The following research by The Prime Buyer's Report identifies the best waterproofing contractors in Marin County and issues related to hiring them.
Updated February 20, 2019
How To Find the Best Waterproofing in Marin County CA
California state licensing for waterproofing companies in Marin County includes the C-61 specialty license and its D51 subcategory for waterproofing and weatherproofing. If the waterproofing company has employees, they are legally required to have workers' compensation insurance to protect you the customer from being sued if an injury occurs during work performed at your property.
You should know that local waterproofing contractors are not required by law to have general liability insurance; however, all waterproofing companies bearing The Prime Buyer's Report Top Ten designation have general liability insurance coverage to reimburse you in the event of any damages, in addition to passing all other requirements for certification as Prime Buyer's Report Top Ten, including our research phone calls to their previous clients, pledging to hire only documented workers, verified license and workers' compensation insurance, clean complaint record, and more.
Waterproofing is most effective when done at the time of construction because concrete is not watertight on its own. One approach is the application of waterproof membranes of various materials like bitumen, silicate, or polymer sheets that act as a barrier between the building and the water. A more recent approach uses additives to the concrete itself, known as integral waterproofing systems.
There are two types of integral systems to give concrete a waterproof quality: hydrophilic which replaces the water in the concrete with crystals, and hydrophobic which uses fatty acids to block pores within the concrete, preventing water passage.
But the need for waterproofing contractors in Marin County often involves solving water leaks, water seepage, and flooding in existing structures, especially cellars, basements, and crawl spaces.
Basement Waterproofing Services and Methods
There are two categories of basement flooding. One is surface water entering the basement from the walls, including windows, wall cracks, pipe penetrations leaks, or basement wall seepage.
The other category is groundwater in the basement through the floor slab, or the cove joint which is where the basement floor and walls meet. This kind of water seepage is referred to as hydrostatic pressure.
Good waterproofing contractors in San Rafael CA and throughout Marin County will start by determining if the flooding is through the walls or through the floor (hydrostatic pressure) or both.
Prevent Basement Flooding from the Walls
Basement water problems are rarely solved by applying waterproof compounds to the interior walls since those interior coatings will degrade over time or can't handle the pressure of water already penetrating the wall.
Cellar dewatering or basement waterproofing is properly done on the exterior, so that water never accumulates around the foundation. This may include grading the soil to keep water at least 15 feet away, installing a drywell if a downhill slope to the foundation is unavoidable, extending gutter downspouts further away from the walls, and correcting window wells that accumulate water.
Avoid Basement Flooding from the Floor Slab (Hydrostatic Pressure)
The amount of ground water can increase with rainfall, causing hydrostatic pressure that pushes water through the cellar floor. The most common solution is installing a drainage system which includes a drainage pipe, gravel or drainage stone, concrete to cover the gravel, and a discharge system consisting of a sump basin and sump pump.
Proper installation of a basement drainage system by a local waterproofing service in Marin County or your area will prevent seepage by removing water before it rises to the level of the basement floor and divert it to a sump well recessed in the floor where a sump pump discharges it elsewhere. Basement drainage systems are usually installed along the interior part of the foundation and can be retrofitted into homes when exterior drainage systems fail or don't exist.
Sump pumps ideally should include a battery back-up to prevent failure during power blackouts since storms can be the common source of both rainfall and power outages.
Crawl Space Waterproofing Services
Originally it was believed that moisture control of crawl spaces was achieved by venting the crawl space to the outside. More recent experience indicates that crawl space venting leads to moisture problems like mold, rot and insects because the moisture level of crawl spaces fluctuates with the outside humidity, while a closed crawl space remains dry.
For existing crawl spaces, waterproofing a crawl space includes fixing water entry problems, closing off the wall vents, installing a full ground moisture barrier (lining the ground with plastic) inside the crawl space. The crawl space should not be closed off if there is unresolved water entry or if furnaces or water heaters are supplied with air from the crawl space. If the hot water heater relief line and drain pan terminate in the crawl space, piping should be added to run these lines to outdoors to prevent overflow from flooding the crawl space.
Installing a crawl space drain will prevent plumbing leaks and water spills from creating standing water on top of the ground moisture barrier (such as ground lining polyethylene). Moldy crawl space air can be prevented from entering the house by sealing floor holes and duct leaks. Closing the crawl space from outdoors includes sealing wall vent openings with rigid foam and sealing with caulk, expanding foam, or mastic, sealing all wall penetrations for electrical and plumbing, and adjusting the crawl space door or access panel for a tight fit.
Sealing a crawl space can reduce moisture levels such that hardwood flooring above it may shrink and show gaps while some previously buckled by moisture have flattened out. Some waterproofing companies may recommend permanently installing a dehumidifier inside the crawl space.
Full-Service Waterproofing Companies vs One-Size-Fits-All
Many Marin County waterproofing contractors offer only one kind of solution, and sometimes that single choice is their own patented system. If your own research or an independent inspection has already determined that's exactly the kind of waterproofing you need, then it can make sense to hire that company.
But if you have not determined yet the exact cause of the problem and the right approach, then a company that sells only one kind of waterproofing might not be the best option. Some waterproofing contractors are full service, meaning they provide multiple options and approaches and can recommend one based on an inspection of your property and determination of the exact causes of water seepage or water leaks in your case.
And remember, cheap waterproofing will not have saved you any money when it fails to work, so think long term, and look for written guarantees that will protect you and your home for several years, decades or for a lifetime warranty.
Some Waterproofing Contractors in Marin County Are A Better Value Than Others
The Prime Buyer's Report lists these contractors for waterproofing in Marin County CA: Urban Waterproofing Inc San Rafael CA, North Bay Waterproofing Inc Kentfield CA, Aquatech Consultancy Inc Novato CA, Westward Builders, Inc. San Rafael CA, Boesel Design & Construction San Anselmo CA, Mares & Dow Construction Concord CA.
Other waterproofing companies in San Rafael CA that might still be in business include: Kelly Waterproofing San Rafael CA, Aqua Stop Waterproofing San Rafael CA, Architectural Restoration & Waterproofing San Rafael CA.
Questions to Ask Waterproofing Contractors in Marin County CA
When it comes to waterproofing in Marin County CA, ask the best local waterproofing companies near you questions about their abilities, experience, and credentials. Some sample questions are listed below. Add to them questions specific to your job and needs.
• How long have the waterproofing companies been providing waterproofing services in Marin County specifically? (Different areas can have unique soil conditions, water table and rainfall issues that it helps to be experienced with.)
• Do the waterproofers provide only one type of waterproofing? What types don't they provide?
• In the case of basement waterproofing services, do the Marin County waterproofing contractors do exterior work or only interior work? If they install basement drain systems, are they above the footing (might be less effective) or sub-floor (below the slab) drainage systems?
• How many other waterproofing jobs have the Marin County waterproofing contractors done of the exact type you're seeking (sub floor interior drains and sump pumps, soil grading, liquid sealants, etc). Different types of waterproofing services require different skills, tools, and experience.
• Can the waterproofing company give you names and numbers you can call as references? (All waterproofing contractors bearing the Prime Buyer's Report—TOP 10 symbol have already had their customer references called by our research staff so you don't have to.)
• How do the local waterproofing companies in Marin County determine pricing?
• Will the waterproofers be performing every stage of the work, or do they use subcontractors?
• Is there a written guarantee? If so, for how many years, and what are the terms?
• Can the waterproofing contractor vouch that all their employees sent to your property are legal to work in the U.S.? (All waterproofing companies bearing The Prime Buyer's Report—TOP 10 symbol have already signed an agreement to only hire documented workers.)
• Do the best waterproofing companies have active workers' compensation and general liability insurance? (All waterproofing contractors bearing The Prime Buyer's Report—TOP 10 symbol have already had proof of insurance verified by our research staff so you don't have to.)
• What inspection work will the Marin County waterproofing contractors provide before preparing an estimate for the waterproofing services and materials needed?
• How long will the waterproofing job take? Does the waterproofing company give any kind of guarantee of completion by your deadline date?
• How well do the waterproofing companies know their crews? Do they personally hire and train their crews, or do they bring them in from the outside on a project-by-project basis?
When you've chosen the best waterproofing contractor in Marin County for your needs, make sure they are still licensed. (All waterproofing companies bearing the Prime Buyer's Report—TOP 10 symbol have already had their license verified by our research staff.)
Resources About Waterproofing in Marin County CA
The following is a list of trade associations and publications related to waterproofing contractors.
Regulatory Bodies & Trade Associations for Waterproofing in Marin County CA
CSLB Contractors State License Board
DCA California Department of Consumer Affairs
Basement Health Association www.basementhealthpros.com
The Waterproofing Contractors Association www.thewaterproofers.org
SWRI (Sealant Waterproofing and Restoration Institute) www.swrionline.org
LRWA (Liquid Roofing & Waterproofing Association) www.lrwa.org.uk
SWA (Sealant and Waterproofing Association) www.swao.com
NAWSRC (National Association of Waterproofing and Structural Repair Contractors) www.nawsrc.org
Publications for Waterproofing Companies in Marin County
Applicator Magazine www.swrionline.org/resources/applicator.asp
Clear Water Repellent Manual www.swrionline.org/store/index.asp?Category=P
Waterproof Magazine www.waterproofmag.com
Architectural Roofing & Waterproofing Magazine www.arwarchitect.com
If you are looking for weatherproofing or waterproofing, The Prime Buyer's Report provides information for the Top Ten waterproofing contractors in Marin County CA within the following zip codes:
94933, 94957, 94973, 94978, 94950, 94971, 94929, 94948, 94966, 94976, 94915, 94913, 94942, 94912, 94977, 94964, 94938, 94963, 94914, 94979, 94937, 94956, 94904, 94947, 94930, 94946, 94925, 94941, 94924, 94940, 94970, 94945, 94903, 94901, 94920, 94965, 94974, 94949, 94939 and 94960
The Prime Buyer's Report provides information for the Top Ten waterproofing companies and waterproofing services in Marin County CA within the following cities:
Bel Marin Keys, Belvedere, Belvedere Tiburon, Black Point, Bolinas, Corte Madera, Dogtown, Fairfax, Greenbrae, Ignacio, Inverness, Kent Woodlands, Kentfield, Larkspur, Marin City, Marinwood, Marshall, Mill Valley, Muir Beach, Muir Woods, Nicasio, Novato, Point Reyes Station, San Anselmo, San Marin, San Quentin, San Rafael, Santa Venetia, Sausalito, Stinson Beach, Strawberry Point, Tamal, Tamalpais Valley, Terra Linda, Tiburon, Dillon Beach, Forest Knolls, Lagunitas, Mission Rafael, Olema, Ross, San Geronimo, Tomales, Woodacre, Almonte, Lucas Valley and Sleepy Hollow