There's a failure mode that looks like great work: a flawless, wall-to-wall membrane, but a floor that's wet again by the next storm. This happens when you seal a wall that's under pressure without ever relieving the pressure. Sealing is only half the job when water has muscle behind it; the other half is giving that water somewhere to go. That's the idea behind System 2+.
If you've read the earlier guides in this series, you already know how to spot the heavy hitter: hydrostatic pressure that shows up on the floor, tracks the weather, and eats the wrong system for breakfast. This is what you do about it from the inside, with no excavation.
The Trap
Sealing a Pressurized Joint Just Moves the Leak
A membrane bonds to the face of the wall and stops water that's trying to come through that face. That's the correct solution when the water is seeping through cracks, porous block, or the field of the wall above the floor line. The coating is the entire fix.
But the wall-floor cove joint is a different animal. Water arriving there, or pushing up through cracks in the slab, is under hydrostatic head from below and behind the floor. It isn't drifting through the wall face; it's being shoved up from under the slab. If you cap that one spot with a membrane, the water doesn't give up and go home, but follows the pressure to the next weakest point: the next crack, the next joint, a few feet down the wall, etc.
You didn't stop the water; you just rerouted it. And to the homeowner, the leak that pops up six feet over next spring looks like a brand-new problem on a wall you just waterproofed.
You can seal against water. You can't seal against pressure. Pressure has to be relieved.
The Decision
Follow the Water, Not the Severity
The choice between System 2 and System 2+ isn't about how dramatic the wall looks. It's about asking one question: where is the water actually coming from? Answer that and the system picks itself.
- •Seepage enters through the wall face: cracks, porous block, above the floor line
- •Light or occasional dampness; the moisture isn't pressurized
- •No water at the cove joint or up through floor cracks
- •No standing water; the water table sits below the slab
- •Water shows up at the cove joint (wall-floor seam) or comes up through floor cracks
- •Standing water, puddling, or outright flooding on the slab
- •High or seasonally rising water table; frequent or continuous sump cycling
- •Head persists after grade and downspout fixes, or those aren't feasible
The Rule of Thumb
Water on the wall → seal it. Water on the floor → seal it AND relieve it.
Seepage through the wall face is a coating problem. Water at the cove joint, up through the slab, or standing on the floor is a pressure problem, and pressure needs a way out, not just a lid.
The System
Same Membrane, Plus a Path for the Pressure
System 2+ isn't a different chemistry; it's the same Phoenix interior sequence that powers System 2 with an interior perimeter drain and sump added at the wall-floor junction. The membrane seals the wall. The drain gives the pressurized water a place to go before it ever reaches the floor surface. Instead of asking a coating to hold back a standing head it was never rated to fight alone, you relieve the head and let the membrane do the job.
Seal the wall
The full Phoenix membrane sequence goes over a prepared, densified substrate. Every crack, cold joint, tie hole, and cove is detailed first, then a base coat applied, then the waterproofing membrane. This is System 2.
Capture the pressure
An interior perimeter drain set at the footing and cove collects the water rising under the slab and at the wall-floor seam, intercepting it below the floor instead of letting it push up onto it.
Evacuate it
The drain feeds a sump basin, and the pump lifts the water out and discharges it away from the foundation. Add a battery backup so a power outage in the middle of a storm (which is when the pump matters most) doesn't become a flooded basement.
A relieved joint stays sealed. Once the drain is carrying the head away, the membrane at the cove isn't fighting a standing column of water, so it isn't being pushed off the wall and the water isn't hunting for the next crack. Seal-and-relieve is what turns a temporary fix into a permanent one.
The Bridge Between System 2 and System 3
System 3 relieves pressure from the outside: excavate, membrane the positive side, and install a footing drain. That's the gold standard when you have full exterior access and it's rated for the heaviest sustained head there is.
But plenty of homes can't or won't be dug up due to finished landscaping, additions over the foundation, tight lot lines, or a budget that won't stretch to excavation. System 2+ is the no-dig answer to heavy water. It includes the same rated interior membrane as System 2, plus active pressure relief. Interior scope, no excavation, standing-water performance, which completes the bridge between System 2 and System 3.
Spec It Right
When to Call System 2+
Walk the basement and run the checklist. Any one of these directs you from “seal it” to “seal and relieve it”:
- Water shows up at the cove joint (wall-floor seam), or comes up through cracks in the floor.
- There's standing water, puddling, or outright flooding on the slab.
- The water table is high or rises seasonally, and the sump runs often.
- The head persists after you've fixed grade and downspouts, or those fixes aren't possible.
- The property can't or won't be excavated, but the water is more than a membrane should fight on its own.
None of these? You're likely in System 2 territory: membrane alone and a cleaner, faster job for it. The point isn't to upsell drainage onto every wall. It's to read the water correctly and match the system to it so you quote it once and it stays dry.
The Products
The Same Sequence, Plus the Relief
System 2+ runs the identical Phoenix product sequence as Systems 2 and 3 in the same non-negotiable order, then adds the interior perimeter drain and sump to carry the pressure away.
Bridging & Joint Compound
A high-viscosity compound that fills and seals every crack, joint, penetration, and cold joint — including the cove — before the base coat. Holds on vertical surfaces.
View Product →Foundation Base Coat
A low-viscosity, self-leveling coat that fills remaining surface irregularities and creates a uniform, well-bonded base for the final membrane.
View Product →Foundation Waterproofer
The final self-leveling membrane. Flexible, crack-bridging, and rated for negative-side interior duty. The seal the relief system protects.
View Product →Interior perimeter drain & sump. Installed with the membrane at the wall-floor junction, the drain captures water under hydrostatic head and routes it to a sump for discharge, relieving the pressure the coating alone can't hold back. Test the pump and its battery backup at least annually and keep the pit clear.
Match the System to the Water
Four pressure-rated systems, one proven prep sequence, from minor vapor control all the way to 250+ PSI. When the water's on the floor, System 2+ seals the wall and relieves the head, no excavation required.
Explore Our Foundation Waterproofing Area →