by michael daigle · 9 Jan 2024You've invested a lot of money in your home or commercial building, so you want to make sure it lasts. One of the biggest threats to any structure is moisture damage, which can lead to rot, mold, and structural issues if left unaddressed. Luckily, there are several waterproofing solutions you can incorporate into your exterior painting to protect your investment from the elements.
The Importance of Waterproofing in Exterior Painting
Waterproofing your home's exterior is crucial to protecting it from damage. As a homeowner, you need to consider waterproofing solutions when it's time for exterior painting.
Why is Waterproofing Important?
Waterproofing seals and protects your home from moisture damage. Without it, water can seep into cracks and crevices, causing issues like mold, rot, and structural damage over time.
Types of Waterproofing
There are several options for waterproofing exterior paint. Silicone sealants and acrylic sealers are popular choices. They penetrate into the surface of the paint, filling in pores to create a waterproof barrier while still allowing moisture vapor to pass through. For high-traffic or weather-exposed areas like porches or railings, a silicone or acrylic sealant is a great choice.
Elastomeric coatings offer maximum waterproofing for your exterior. Made from acrylics, urethanes or silicones, they create a rubbery, flexible coating that expands and contracts with the surface. Elastomerics require two coats for the best protection but can last 10-15 years.
Application
Proper application of your waterproofing solution is key. Clean and prepare the surface, then apply at least two coats of your chosen sealant or coating, waiting for each to dry as directed. For the best results, apply in the proper temperature range and avoid painting if rain is in the forecast.
With regular inspections and touch-up as needed, a high-quality waterproofing solution can help ensure your home's exterior lasts for years to come. Protect your investment and give your home the defense it deserves against the elements.
Common Sources of Moisture Damage on Building Exteriors
Moisture damage is one of the biggest threats to a building's exterior. As a homeowner, it's important to identify common sources of moisture to prevent costly damage.
Roof Leaks
A leaky roof is enemy number one. Even small leaks can lead to water seeping into attics, walls and basements if left unaddressed. Inspect your roof regularly, especially after heavy rains or snowstorms. Look for visible water spots, peeling paint or sagging gutters which can channel water into the roof.
Gutter Overflow
Clogged or damaged gutters unable to properly divert rain and snowmelt can result in moisture pooling along foundations and seeping into basements or crawlspaces. Clean out gutters and downspouts annually to remove leaves and debris. For added protection, extend downspouts away from the building to move water away from the foundation.
Ground Water
Water collecting along foundations, known as ground water, is a common culprit of moisture damage. Improve drainage around the building by re-grading the soil to slope away from the foundation and installing drains or sump pumps if needed. Waterproofing products like sealants, membranes and coatings create an impenetrable barrier when applied to foundations and basements.
Condensation
Warm, moist air condensing on cool surfaces creates condensation which can lead to water damage, especially in attics and basements. Increase ventilation and insulation which helps regulate temperature and control humidity levels in the home. Avoid drying clothes indoors or using unvented heaters, stoves or ovens which produce excess moisture.
By identifying and addressing these common moisture sources, you can help prevent damage to your building's exterior and avoid costly repairs down the road. Through regular inspections and preventative maintenance, you'll keep your home safe, dry and protected.
Selecting the Right Waterproofing Paints and Coatings
When it comes to exterior painting, selecting high-quality waterproofing paints and coatings is key to protecting buildings from moisture damage.
Waterproof Paint
For the best protection, choose paints specifically meant for exterior use that are waterproof or water-resistant. These are formulated with waterproofing sealants and acrylic resins that form a durable barrier against the elements. Popular options include:
- Latex or acrylic paint: Water-based, flexible and breathable. Resists cracking and peeling. Use on most exterior surfaces.
- Oil-based paint: Waterproof and weather-resistant but has strong fumes. Use on wood, metal.
- Elastomeric paint: Highly waterproof and flexible. Expands and contracts with surface. Use on concrete, stucco, masonry.
Waterproof Sealers and Primers
For the ultimate waterproofing, apply a waterproofing sealer or primer before painting. These penetrate into the surface to form a waterproof undercoat. Top options include:
- Waterproofing sealers: Penetrating sealers, often silicone-based, that waterproof wood, concrete, masonry.
- Waterproofing primers: Primers infused with waterproofing agents. Use under paint on any exterior surface. Help paint adhere better for longer-lasting results.
- Epoxy primers: Two-part primers that chemically bond to surfaces. Extremely durable and waterproof. Use on concrete, metal and wood before painting.
Elastomeric and Waterproof Coatings
For problem areas like foundations, roofs, decks and patios, waterproof elastomeric or roof coatings provide an ultra-protective topcoat. These thick, rubbery coatings:
- Expand and contract with the surface, bridging cracks.
- Waterproof and weatherproof, lasting 10-15 years.
- Come in water-based and solvent-based options for different needs.
- Require proper surface preparation to adhere well.
Using high-quality, waterproofing paints, primers, sealers and coatings suited to your needs will help ensure long-lasting protection from moisture damage for your building’s exterior. Be sure to clean, repair and prepare surfaces properly before applying for the best results.
Prepping Surfaces for Waterproofing Paints
To ensure the best results from your waterproofing paint, proper surface preparation is key. Clean, dry, and primed surfaces allow paint to adhere fully, preventing moisture damage for years to come.
Clean Surfaces Thoroughly
Remove all dirt, grease, and grime from exterior surfaces before painting. Pressure wash siding and trim to blast away built-up dirt and debris. For stuck-on messes, scrub with a degreaser or heavy-duty cleaner and rinse well with water. Allow all areas to dry completely before priming or painting.
Fix Any Damage
Inspect siding and trim for any cracks, holes, or rotted areas and repair or replace damaged materials. Caulk gaps and seams to create a solid, watertight surface. For wood, apply a wood filler or patch compound, then sand smooth. Larger repairs may require replacing boards or siding panels. Fixing damage before painting ensures the best protection.
Apply a Primer
Primer helps paint adhere fully to surfaces, especially on bare wood or porous materials like concrete. For the most effective waterproofing, use an oil- or alkyd-based primer followed by two coats of waterproofing paint. On previously painted surfaces in good condition, a primer may not be needed. Check your specific paint product recommendations to determine if priming is required for your project.
Consider a Sealant for Concrete
For concrete foundations, porches, steps and walkways, apply a concrete sealant before painting for the best protection. Sealants penetrate into the concrete to waterproof from within while also priming the surface for paint. For high-traffic or frequently wet areas like pool decks, a non-skid additive can be mixed into the sealant for added traction.
With the proper prep, your waterproofing paint will keep moisture out and prevent damage to exterior surfaces for maximum durability. Cleaning, fixing damage, priming, and sealing are small steps that make a big difference in how well your paint protects from weather and water.
Applying Waterproofing Paints and Sealants
To protect buildings from moisture damage, waterproofing paints and sealants should be applied to exterior walls. These products create a protective barrier against water while still allowing walls to breathe.
Choose a Waterproofing Paint
Select a paint specifically designed for waterproofing exterior masonry like concrete, stucco or brick. These paints contain additives to improve water resistance and durability. Popular options include acrylic latex paints, elastomeric paints and cementitious paints like those containing silicone. Test the paint on an inconspicuous area first to check adhesion and appearance.
Apply a Primer
For the best results, start with a primer. A primer helps the waterproofing paint bond strongly to the wall surface. For bare masonry, use a primer designed for that specific surface. For previously painted walls, an all-purpose primer will work. Apply at least one coat of primer and let it dry completely.
Roll on the Waterproofing Paint
Use a brush to paint edges and corners, then roll the rest of the wall using a high-quality roller cover with a thick nap, like 3/4-inch. Apply at least two coats of the waterproofing paint, waiting for each coat to dry completely between applications. More coats provide better protection.
Seal Joints and Cracks
Inspect the walls for any cracks or gaps around doors, windows, pipes or other penetrations. Clean and fill small cracks with caulk or concrete patch compound. For larger cracks, you may need to apply a concrete sealer or waterproofing membrane before painting. Sealant tapes can also be used around doors and windows.
Re-Paint Every Few Years
Even with a waterproofing paint, exterior walls may start showing signs of water damage after 3 to 5 years. Plan to re-paint walls on a regular basis to maintain protection. Touch up any problem areas in between to prevent moisture from seeping in. With diligent upkeep, waterproofing paints provide an economical solution to keeping building exteriors in top condition.
Inspecting and Maintaining Waterproofed Surfaces
To keep your waterproofed surfaces in good working order, regular inspections and maintenance are key.
Inspect Annually
Make it a point to inspect waterproofed areas at least once a year, ideally in the spring. Look for any signs of damage or deterioration like cracks, holes, peeling, or blistering. Also check places where waterproofing meets other materials like windows, doors or pipes for proper adhesion. If you spot any issues, repair or reapply waterproofing as needed to prevent leaks.
Reapply every 3-5 years
As a general rule of thumb, reapply waterproofing coatings every 3 to 5 years to maintain protection. Weathering and sun exposure can break down sealants and coatings over time. Reapplying a fresh coat before the old one starts to fail will help ensure continuous protection for your building.
Clean regularly
Dirt, debris, and stains on waterproofed surfaces can reduce effectiveness and shorten lifespan. Clean waterproofed areas regularly using a pressure washer or scrub brush with detergent and water. Be careful not to damage the coating. Rinse well with water to remove all residue when done cleaning.
Seal cracks and holes
Unsealed cracks, seams, and holes in waterproofed areas provide easy access for water to get in. Inspect regularly for any openings and seal them up right away using a waterproof caulk, sealant, or roof cement and roof flashing or patches for larger holes.
Slope areas properly
Make sure waterproofed areas like roofs, decks, and balconies slope properly to allow for drainage. Standing or pooling water can lead to leaks over time as it deteriorates the waterproofing. Repair or re-slope areas as needed to promote runoff.
With regular care and maintenance, your building’s waterproofed surfaces should provide many years of protection from the elements. Be diligent about inspections and don’t delay repairs or reapplications when needed. Your proactive efforts will help ensure a long lifespan for your waterproofing solutions.
Advanced Waterproofing Options Like Membranes
Advanced waterproofing options like membranes provide superior protection for exterior surfaces. These high-performance solutions create an impenetrable barrier between the building envelope and moisture.
Elastomeric Coatings
Elastomeric coatings, also known as rubberized coatings, are thick, flexible sealants that can stretch and retract with the expansion and contraction of building materials. They are highly resistant to water penetration and cracking. Elastomeric coatings typically contain acrylics, urethanes or silicones and provide a durable, seamless coating.
Liquid Applied Membranes
Liquid applied membranes are coatings that cure to form a rubbery, watertight seal. They are typically made of acrylic, polyurethane, or modified bitumen and can be applied with a roller, brush or spray equipment. Liquid applied membranes provide excellent adhesion and durability. They are well suited for complex roof shapes and details.
Peel and Stick Sheets
Pre-formed peel and stick sheets, like EPDM or TPO, provide a simple waterproofing solution. The sheets are made of rubber or thermoplastic materials with a pressure-sensitive adhesive backing that sticks firmly to surfaces. Peel and stick sheets are waterproof, UV-resistant, and long-lasting. They can be cut to fit any shape and are easy to install, even for DIYers.
PVC or TPO Membranes
Polyvinyl chloride (PVC) and thermoplastic olefin (TPO) membranes are popular single-ply roofing and waterproofing materials. They are made of durable, flexible plastics and installed by heat or chemically fusing the seams. PVC and TPO membranes are energy efficient, environmentally friendly, and provide decades of water tight protection. Professional installation is typically required for these systems.
Waterproofing exterior walls and roofs is critical to protecting buildings and their contents from water damage. Advanced solutions like elastomeric coatings, liquid applied membranes, peel and stick sheets, and PVC/TPO membranes provide superior, long-term protection for building envelopes. With options at varying price points, there’s a high-performance waterproofing solution for any project.
Signs Your Building Needs New Waterproofing
If your building is showing signs of water damage or leaks, it's probably time for new waterproofing. Here are some indications you need to call a professional waterproofing contractor.
Have you noticed damp, musty spots on walls or floors, especially in the basement or attic? Excess moisture can lead to mold growth, structural damage, and health issues.
Do you see water stains, cracks, or crumbling spots on exterior walls, roofs, balconies, or patios? Water is finding its way in, and waterproofing seals and coatings need repair or replacement.
Has your energy bill gone up recently? Poor insulation from water damage reduces efficiency. Properly waterproofing and re-insulating can lower utility costs.
Do gutters, downspouts, or drains flow poorly or clog frequently? Improper water runoff stresses waterproofing systems and allows water to pool near foundations. Install gutter guards and clear clogs, then reapply waterproofing for best results.
Have there been any leaks or floods in the building? Even if repaired, waterproofing may still need reinforcement to prevent future incidents. It’s best to consult an expert.
Does moisture form on walls or windows? Condensation forms when warm, moist air meets cold surfaces. New waterproofing, insulation, ventilation, or dehumidification can help.
Do you notice musty smells, especially in little-used areas? Excess moisture promotes the growth of mold, mildew, and other microbes that release foul odors. Waterproofing and improved ventilation can eliminate the problem.
If you spot any of these signs in your building, it’s important to take action quickly to avoid costly damage. Call a professional waterproofing company to thoroughly inspect the structure and recommend appropriate solutions like sealants, membranes, coatings to keep your building safe, dry, and protected for years to come.
Waterproofing Solutions FAQ - Your Top Questions Answered
Your top questions about waterproofing solutions for exterior painting are answered here.
What is waterproofing paint?
Waterproofing paint, also known as elastomeric or rubberized paint, is a coating designed specifically to seal and protect exterior surfaces from moisture damage. It contains elastic polymers that allow it to stretch and flex with the surface as temperatures change. This helps prevent cracking that can lead to water intrusion.
How does it work?
Waterproofing paint forms a durable, water-resistant plastic coating over the exterior substrate. As water hits the surface, it beads up and rolls off instead of soaking in. The elastomeric properties of the paint also allow it to expand and contract with the surface during temperature changes without cracking. This combination of water resistance and flexibility provides superior protection from the elements.
When should I use it?
You should consider using waterproofing paint if you have a surface that is exposed to excessive moisture like:
- Stucco, concrete, cinder block or brick exteriors
- Areas around swimming pools, hot tubs or fountains
- Surfaces with a history of water damage or leakage
- Basements, foundations or retaining walls
- Roofs, gutters, downspouts or flashing
- Decks, patios or balconies
How is it applied?
Waterproofing paint is typically applied with a brush, roller or sprayer in 2-3 coats. For the best results:
- Clean and repair any surface damage before painting.
- Apply a primer for the best adhesion, especially on bare or porous surfaces.
- Follow the recommended drying time between coats for proper curing.
- Use a paint with a satin or glossy sheen for maximum water resistance. Flat paints offer little protection.
- Inspect the painted surface regularly and recoat as needed to maintain protection.
How long will it last?
When properly applied to a well-prepared surface, waterproofing paint can last 3-5 years or more before requiring a touch up or recoat. Harsher weather conditions, excessive sun exposure, and the quality of the paint will affect longevity. Annual inspections are a good idea to ensure continued protection.
Final Thoughts
You want your building to last, so protecting it from the elements is key. By using specialized waterproofing solutions in your exterior paint, you can shield your structure from moisture damage for years to come.
A few extra dollars spent now on high-quality, water-resistant paint will save you thousands down the road in repairs and renovations. When it comes to your property, an ounce of prevention is worth a pound of cure.
Do right by your building and protect your investment. Opt for waterproofing solutions like silicone additives and elastomeric paints for your exterior. You'll rest easy knowing water will simply bead up and roll off, leaving your building dry as a bone. The peace of mind that comes from a well-maintained and protected structure is priceless.