Make every deck you
build a little better
See what happens when you put water in its place.
Introducing UnderDeck Shield™
The surprisingly affordable, amazingly simple way to control drainage and create dry, usable space.
A smart solution for everyday drainage control
UnderDeck Shield is an effective, affordable solution suitable for virtually any deck.
It captures and channels water, transforming the space underneath decks into dry, usable space. Its adaptability and simple installation make it a must-have upgrade for any new or existing deck. Whether your goal is to create usable space below a deck, or divert rainwater away from the home’s foundation, UnderDeck Shield does it all with ease. Lightweight and durable, it puts water in its place.
-
Compatible on all decks
UnderDeck Shield is compatible
with virtually every style of deck.New or existing decks
Ground-level or elevated decks
Natural wood or composite -
Effective Drainage System
Patented design with integrated slope directs water away from your home’s foundation.
Create dry, usable space
Protect foundation
Prevents joist rot -
Easy Installation
Lightweight panels are easy to handle and installation requires minimal tools.
Easy to install
DIY-friendly
Affordable -
Decorative Finish
Brings a fresh, finished look to the underside of second-story decks.
Shiplap finish hides green-treated lumber
Brightens and freshens appearance
Creates a more finished look
Take in the overview
Make every deck you build a little better
See what happens when you put water in its place.
Introducing
UnderDeck Shield™
The surprisingly affordable, amazingly simple way to control drainage and create dry, usable space.
A smart solution for everyday drainage control
UnderDeck Shield is an effective, affordable solution suitable for virtually any deck.
It captures and channels water, transforming the space underneath decks into dry, usable space. Its adaptability and simple installation make it a must-have upgrade for any new or existing deck. Whether your goal is to create usable space below a deck or divert rainwater away from the home’s foundation, UnderDeck Shield does it all with ease. Lightweight and durable, it puts water in its place.
-
![]()
Compatible on all decks
UnderDeck Shield is compatible
with virtually every style of deck.New or existing decks
Ground-level or elevated decks
Natural wood or composite -
![]()
Effective Drainage System
Patented design with integrated slope directs water away from your home’s foundation.
Create dry, usable space
Protect foundation
Prevents joist rot -
![]()
Easy Installation
Lightweight panels are easy to handle and installation requires minimal tools.
— Easy to install
— DIY-friendly
— Affordable -
![]()
Decorative Finish
Brings a fresh, finished look to the underside of second-story decks.
Shiplap finish hides green-treated lumber
Brightens and freshens appearance
Creates a more finished look
Take in the overview
HOW IT WORKS:
Built-in slope ensures water flows away from the home’s foundation
The 47.5” x 33.5” overlapping panel system makes installation easy and intuitive
THE INTERLOCKING SYSTEM IS AS SIMPLE AS A-B-C
Part A is placed over the joist starting at the house
Part B is then placed over the joist and under the end of Part A
Part C is then placed over the joist and under the end of Part B
Gutter and downspout can be easily added
FAQs
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A traditional 12' x 14' deck will require X A panels, X B panels and X C panels.
Panels are engineered for 16" on-center joist spacing, but panel width can be easily modified to accommodate variable joist spacing.
If you have a deck that has multiple variable joist spacing, or if joists are uniformly under 16" spacing, please contact info@underdeckshield.com for detailed ways to work around this issue.
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The average MSRP for the panels needed to be installed above or below a a 12'X14' deck is around $2,000, or about $xxx/square foot.
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Each panel is 47 1/2” x 33 ½”, covers approximately 11 square feet, and rests on top of three joists:
Depth 4 ft → Panel A only
Depth 8 ft → Panels A + B
Depth 12 ft → Panels A + B + C
For wider decks, add more panel sets side-by-side. Our precise product calculator (coming soon) will tell you exactly how much product you will need for your deck. Simply add your deck dimensions, and we’ll figure out the rest.
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Yes. The system is made of weather-resistant composite material, Thermoplastic Polyolefin (TPO). TPO is lightweight, durable, and stands up to rain, snow, and UV exposure.
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Currently available in Soft White. More colors and styles are coming soon.
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Yes. By diverting water away from the home, UnderDeck Shield helps protect joists from rot, mold, warping, and premature wear, ultimately avoiding maintenance costs and extending the life of your deck.
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The UnderDeck Shield panel product will be available to order in 2026. If you have any project requests or questions in the meantime, please reach out to info@underdeckshield.com.
THE INTERLOCKING
SYSTEM IS AS
SIMPLE AS A-B-C
Gutter and downspout can be easily added
Part A is placed over the joist starting at the house
Part B is then placed over the joist and under the end of Part A
Part C is then placed over the joist and under the end of Part B
Let’s work together
We’re looking for partners… drop us a line and we’ll get back to you.
PATENTED PROCESS
UnderDeck Shield’s patented lightweight panels are engineered to fit together seamlessly, shielding the space underneath and directing water away from the foundation of your home.
PATENTED PROCESS
UnderDeck Shield’s patented lightweight panels are engineered to fit together seamlessly, shielding the space underneath and directing water away from the foundation of your home.
