Dry below · And a frame that lasts longer
Under-Deck Waterproofing in Cincinnati
A drainage system under a raised deck sends what lands on the boards out to a gutter instead of raining through onto whatever is below. It gives you a dry patio for the price of a ceiling. It is the cheapest square footage you will ever add, because the roof and the posts already exist. The part nobody sells it on is that it also keeps the joists dry, and that is worth more than the patio.
What under-deck waterproofing actually involves
There are two ways to do it and the difference matters. An over-joist system goes on top of the framing before the decking, so water never touches the structure at all, and the joists stay dry for the life of the deck. An under-joist system hangs below the framing, so water still passes through the boards and over the joists before it is caught. Both give you a dry space underneath; only one protects the frame.
That makes the timing worth knowing early. Over-joist goes in with the decking off, so it is nearly free on a new deck or a redeck, and under-joist retrofits to a deck that is staying exactly as it is. What either one buys is a room. The space under a second-story deck is usually wasted, and drained and ceilinged it takes patio furniture, a television, lighting and a fan, shaded and dry in exactly the weather that drives everybody off the deck above.
What is included in under-deck waterproofing
The right system for your timing
Over the joists if the boards are off, under them if the deck is staying. Either way you get a dry, usable space underneath.
Fall, gutter and a real downpipe
Water is collected and taken somewhere, not simply dripped off the edge of the deck onto the ground you were trying to keep dry.
Ventilation kept open
Ours keeps a path for air through the frame, so the space below stays dry and the timber holding it up stays dry with it.
What to check under a raised deck
Four things worth checking under a raised deck, ideally with a flashlight and after it has rained.
The ground under the deck never dries out
Everything landing on the boards is going straight through. It is why nothing stored under there survives, and it is why the posts at that end are usually the first to go.
Dark staining along the top edges of the joists
Water running off the underside of the decking and sitting on the joist above every fastener hole. That is where rot starts in a frame that otherwise looks fine.
You are storing nothing under a large dry-ish space
A second-story deck typically covers 200 to 400 square feet of ground. If it is unusable, that is the cheapest room in the house going to waste.
Water pooling against the foundation after rain
The deck is concentrating roof-sized volumes of water into one strip of ground beside the house. Drainage with a proper downpipe moves it somewhere sensible.
Worth knowing
Over-joist against under-joist
Over-joist systems, which are membrane or panels laid on top of the framing and under the decking, keep the whole structure dry. The joists never see water and the fastener holes never fill. They can only go in with the decking off.
Under-joist systems hang below the frame and catch what has already run over the joists. Same dry space below, and the only option on a deck that is staying as it is. They solve different halves of the problem, and the boards decide which one you can have.
Ventilation is the part we design around
The instinct is to close everything in: panels tight to the joists, a sealed ceiling below, nothing left open. That gives you a sealed cavity over damp ground with no air moving through it, and timber in a sealed damp cavity does worse than timber that gets rained on and dries out.
Ours leaves a path for air through the frame and does not seal the perimeter, so the space below stays dry without trapping damp against the timber holding it up. It is on the drawing before the first panel is ordered.
FAQ
Under-Deck Waterproofing questions
What is under-deck waterproofing?
A system that catches the water passing between deck boards and drains it to a gutter, so the space underneath a raised deck stays dry and usable. It comes in two forms: over-joist, laid on the framing before the decking, which also keeps the frame dry; and under-joist, hung below the framing, which can be retrofitted to a finished deck.
Can it be added to a deck I already have?
Yes, using an under-joist system. That is exactly what they exist for, and it gives you the same dry room underneath on a deck you are keeping as it is. If a redeck is already on the cards, say so and we fit the over-joist system while the boards are off, which is the cheaper install and keeps the frame dry as well.
Does it stop the deck frame rotting?
An over-joist system does, because water never reaches the joists at all. That is the argument for fitting it while the boards are off, and on a new deck or a redeck it adds very little to the job. An under-joist system gives you the same dry room below on a deck that is staying as it is, which is what most people are asking for.
Is it worth it on a low deck?
It earns its money from about 30 inches of height up, and it gets better the higher the deck is. On a second-story deck you are gaining a room: a dry, shaded space that takes furniture, a television and lighting. That is the cheapest square footage you will ever add to a house, because the roof and the posts are already there.
Where does the water actually go?
Into a gutter along the low edge, into a downpipe, and away from the house. That last part matters: a system that discharges at the base of the foundation wall has concentrated a roof-sized volume of water in the worst possible place. It gets piped out to somewhere sensible, the same as any other downpipe.
Can I put a ceiling and lights under there?
Yes, and it is what turns it from a dry gap into a room. The ceiling goes below the drainage tray, and the fan-rated boxes, lighting and outlets are roughed in before it closes up. Retrofitting electrical into a finished under-deck ceiling means taking the ceiling down again.
Will it make the space under the deck damp?
No. Ours keeps a ventilation path through the framing and leaves the edges open, so air keeps moving through the frame while the water is caught above it and taken away to a gutter. That detail is on the drawing before the first panel is ordered.
We bring your vision to life
Most of our work starts as a sketch on a kitchen table. A door that opens onto a drop, a slope nobody wants to mow, a corner the sun ruins at four in the afternoon. We measure it, draw it, price it line by line, and build the deck you signed off on rather than the one that was easiest to frame.
Bulldog 6 step process
A deck that is still tight in fifteen years is not an accident of good lumber. It is the result of standards you can count on.
Design & Layout
We measure up, then agree the size, the shape, the materials and where the steps go. You get a drawing and an itemized price before anything is ordered.
Engineering & Permit
We draw the plans, get them stamped by an engineer where the county asks for it, submit them and pull the permit. Inspections are booked and the boards go on order.
Demolition & Footings
The old deck leaves in a dumpster the same week. The utility locate goes in two working days before digging, the footings go below the frost line, and the holes are inspected before concrete.
Framing & Flashing
We bolt the frame to the house and flash where the two meet, so rain runs off instead of into the wall. The county inspects it before any decking covers it.
Decking & Railing
Boards go down with the right gaps, the railing is built to take a grown adult leaning on it, and every step is the same height. We sweep up daily.
Inspection & Sign-Off
We walk the finished deck with you and fix your list before the final payment. That last pass is the Bulldog Finish, and the paperwork is yours to keep.
Our work
Decks we have built
Covered deck with a stone fireplace and a mounted screen
String lights over a deck at dusk
Who you are hiring
Cincinnati deck builders since 2001
A family-owned crew out of Cincinnati, covering both sides of the river and the communities around it.
What we are good at is structure that has to last. We are not the cheapest quote you will get, and the difference is under the boards rather than on top of them.
- 1,400+ decks built and rebuilt since 2001
- Built for freeze-thaw winters and clay that heaves
- W-2 carpenters on payroll, never subcontracted out
- Permits pulled in every jurisdiction we work in
- Written, itemized estimates before you commit
Why homeowners choose us
What makes us different
Six things you can check before you sign anything, and hold us to afterwards.
- Family-owned and operated since 2001
- Licensed and fully insured
- 4.9 stars from 600+ reviews
- Financing available
- Decks built to last through Ohio winters
- Composite, wood, covered decks and pergolas
In their words
What homeowners say
Great experience from the entire team. Very professional contractors, who deliver on their design (which by the way are spot on!). I hope to use them more in the future. My wife and I are excited to use our new deck with the entire family. Shout out
There is a reason why Bulldog Deck is an award winning company. Each time we step out onto our amazing deck, we are reminded of the all the designing, planning and constructing that puts them at the top. My wife found Bulldog Deck and was impressed
My family and I couldn't be happier with our new outdoor living space and Bulldog Deck were extremely professional throughout the entire process and the end result was just amazing! As important is the follow up and customer support that we
Related services
Financing available
Spread it across the year, not the month
A new deck is one summer of work, and our financing menu is built so it does not have to be one summer of savings. Spread it across the year on approved credit and the deck goes in this season.
On approved credit. Terms vary by lender and project size.
Materials
Decking materials we build with
Pressure-treated pine
The most affordable and most common choice, and it takes a stain beautifully every time we re-coat it.
Redwood and cedar
Naturally resistant to rot and insects, with a rich warm color and a softer feel underfoot.
Tropical hardwoods
Ipe, tigerwood and cumaru. Dense enough to shrug off dents, insects and rot for decades.
Capped composite
Recycled wood fiber and plastic wrapped in a protective polymer shell. No annual sealing.
Advanced PVC
Fully synthetic with no wood content. Light, highly moisture-resistant and cooler underfoot in sun.
Aluminum
Fireproof, rust-proof and bug-proof, and lasts a lifetime with almost no upkeep.
Where we work
Proudly decking the Tri-State
Cincinnati and Surrounding Areas: southwest Ohio, Northern Kentucky and southeastern Indiana. 170 communities, covered by our own crews.
Counties & cities we serve
Hamilton County, OH
- Cincinnati
- Blue Ash, OH
- Norwood, OH
- Montgomery, OH
Butler County, OH
- West Chester, OH
- Hamilton, OH
- Fairfield, OH
Warren County, OH
- Mason, OH
- South Lebanon, OH
- Maineville, OH
Clermont County, OH
- Milford, OH
- Batavia, OH
- New Richmond, OH
Kenton County, KY
- Covington, KY
- Fort Mitchell, KY
- Erlanger, KY
Campbell County, KY
- Newport, KY
- Fort Thomas, KY
- Bellevue, KY
Boone County, KY
- Florence, KY
- Union, KY
- Burlington, KY
Dearborn County, IN
- Lawrenceburg, IN
- Aurora, IN
- Greendale, IN
No obligation
Get a written estimate, not a guess
We walk the job, measure it, and leave you with an itemized number. No obligation and no follow-up pressure.
Request your estimate
Most estimates are scheduled within two business days.
Under-Deck Waterproofing in 170 neighborhoods covered by Bulldog Deck
Cincinnati Neighborhoods(52)
- Sedamsville
- Sayler Park
- Riverside
- East Price Hill
- West Price Hill
- Lower Price Hill
- Over-the-Rhine
- Downtown
- West End
- Mount Adams
- Mount Auburn
- Clifton
- Corryville
- Northside
- College Hill
- Walnut Hills
- East Walnut Hills
- Avondale
- Hyde Park
- Oakley
- Mount Lookout
- Columbia-Tusculum
- Mount Washington
- Madisonville
- Pleasant Ridge
- Westwood
- Pendleton
- Queensgate
- CUF
- Camp Washington
- South Fairmount
- East End
- North Fairmount
- Evanston
- South Cumminsville
- English Woods
- North Avondale
- Millvale
- Paddock Hills
- Spring Grove Village
- Linwood
- Bond Hill
- Villages of Roll Hill
- East Westwood
- Western Hills
- California
- Carthage
- Winton Hills
- Roselawn
- Mount Airy
- Hartwell
- Kennedy Heights
Hamilton County, OH(54)
- Norwood
- Blue Ash
- Montgomery
- Madeira
- Wyoming
- Mariemont
- Cheviot
- Covedale
- St. Bernard
- Elmwood Place
- Delhi Hills
- Golf Manor
- Fairfax
- Mack
- Monfort Heights
- Bridgetown
- Finneytown
- Amberley
- Arlington Heights
- North College Hill
- Newtown
- Turpin Hills
- Silverton
- Lockland
- Groesbeck
- Mount Healthy
- Reading
- Dent
- Deer Park
- Terrace Park
- Dry Run
- White Oak
- Forestville
- Cherry Grove
- Kenwood
- Lincoln Heights
- Dillonvale
- Woodlawn
- Addyston
- Greenhills
- Northbrook
- Indian Hill
- Evendale
- Glendale
- Sharonville
- Northgate
- Springdale
- Miamitown
- Forest Park
- Pleasant Run
- Cleves
- North Bend
- Loveland
- Harrison
Clermont County, OH(16)
- Mount Carmel
- Summerside
- Withamsville
- Milford
- Mulberry
- Mount Repose
- Day Heights
- New Richmond
- Amelia
- Batavia
- Owensville
- Goshen
- Moscow
- Newtonsville
- Williamsburg
- Bethel
Butler County, OH(9)
- West Chester
- Ross
- Fairfield
- Beckett Ridge
- Wetherington
- Hamilton
- Millville
- New Miami
- Monroe
Warren County, OH(6)
- Mason
- Landen
- Loveland Park
- Maineville
- Pleasant Plain
- South Lebanon
Kenton County, KY(15)
- Covington
- Erlanger
- Ludlow
- Park Hills
- Bromley
- Fort Wright
- Fort Mitchell
- Villa Hills
- Lakeside Park
- Crescent Springs
- Crestview Hills
- Edgewood
- Taylor Mill
- Elsmere
- Independence
Campbell County, KY(10)
- Newport
- Bellevue
- Fort Thomas
- Dayton
- Southgate
- Wilder
- Highland Heights
- Cold Spring
- Alexandria
- Melbourne
Boone County, KY(5)
- Florence
- Hebron
- Burlington
- Union
- Walton
Dearborn County, IN(3)
- Lawrenceburg
- Greendale
- Aurora