Posted by Spycor Building on Mar 14th 2025
DELTA®-MS is a dimpled high-density polyethylene (HDPE) foundation membrane made by Dörken Systems. It is installed with the dimples against below-grade walls, which creates an 8 mm air gap. That gap acts as a capillary break and lets incidental water drain down to the footing drain. DELTA®-MS is evaluated under ICC-ES ESR-2303 as foundation dampproofing (IBC and IRC) and as wall waterproofing under the IRC.
DELTA-MS at a Glance
| Spec | DELTA®-MS |
|---|---|
| Manufacturer | Dörken Systems Inc. (DELTA® brand) |
| Product type | Dimpled HDPE below-grade sheet membrane |
| Material | Co-extruded HDPE: 60% recycled core, 40% virgin outer layers |
| Thickness | 28 mil (0.7 mm) |
| Dimple height | 0.31 in (8 mm) |
| Compressive strength | 5,200 lbs/ft² |
| Roll length | 65.6 ft |
| Roll widths at Spycorbuilding.com | 5'0", 6'7", 7'0", 8'0", 9'10" |
| Code evaluation | ICC-ES ESR-2303 (IBC/IRC), CCMC dampproofing and drainage (Canada) |
| Code use | Dampproofing (IBC and IRC); wall waterproofing (IRC, low hydrostatic pressure) |
| Substrates | Cast-in-place concrete, concrete block (parged), ICF, treated wood foundations |
| Maximum wall height | 16 ft |
| Sustainability | Declare Red List Free; no VOCs |
What Is DELTA-MS?
DELTA®-MS (often searched as "Delta MS" or "Delta-MS") is Dörken's dimpled foundation membrane. It protects below-grade walls from soil moisture and water. It is a semi-rigid HDPE sheet with a vacuum-formed dimple pattern on one side. Contractors unroll it against the exterior foundation wall, fasten it at the top, and backfill against it.
It sits in the same product family as DELTA®-DRAIN and DELTA®-MS UNDERSLAB. DELTA®-MS itself is the vertical foundation wall membrane that homebuilders, foundation contractors, and waterproofing subcontractors specify most often.
How DELTA-MS Works: Air-Gap Technology
DELTA®-MS protects the wall in two ways:
- Capillary break. The impermeable HDPE sheet keeps wet soil and groundwater from touching the concrete, which stops moisture from wicking into the wall.
- Gravity drainage. The dimples hold the sheet off the wall and form a continuous air gap. Any moisture that condenses in that gap, including construction moisture from new concrete, flows down to the footing and into the perimeter drain.
Because the membrane is a separate sheet rather than a coating bonded to the concrete, it keeps working if the foundation settles or cracks. A spray-applied coating cracks when the wall cracks. DELTA®-MS bridges the crack.
Is DELTA-MS Waterproofing or Dampproofing?
Both, depending on the code and the project. This is the most common question buyers ask, so here is the precise answer:
| Code / Jurisdiction | How DELTA®-MS Is Recognized |
|---|---|
| IRC (most single-family and residential) | Foundation dampproofing and wall waterproofing in low hydrostatic pressure conditions, such as sites with perched water tables |
| IBC (commercial) | Foundation dampproofing. Use as standalone waterproofing under the IBC is outside the scope of ESR-2303. |
| Canada | CCMC-evaluated as dampproofing and as a drainage layer |
What this means for your project:
- Homebuilders (IRC work): DELTA®-MS can serve as the foundation waterproofing system on its own. No spray coat is needed first.
- Commercial contractors (IBC work): Specify DELTA®-MS as dampproofing, or as a drainage and protection layer over the project's specified sheet or fluid-applied waterproofing. It shields that membrane from backfill damage and gives it a drainage path.
- High water tables or hydrostatic pressure: Follow the foundation designer's waterproofing specification. DELTA®-MS complements that system rather than replacing it.
Why Homebuilders and Contractors Choose DELTA-MS
- No cure time. It goes on as soon as forms are stripped. You don't wait for the concrete to cure or for spray fumes to clear.
- No special equipment or PPE. Crews install it with fasteners, sealant, and termination trim.
- All-weather installation. Rain and cold don't stop the job the way temperature windows stop liquid coatings.
- Fewer callbacks. It bridges wall cracks and keeps working through settlement, which is where spray dampproofing typically fails.
- Backfill protection. The tough dimpled sheet resists damage from rocks and debris during backfill.
- Proven durability. Virgin HDPE outer layers protect the recycled core from oxidation and chemical stress cracking in acidic or alkaline soils.
- Healthier basements. Keeping the wall dry reduces interior dampness and musty odors, and the product has no chemical odors or VOCs.
- Green building credit support. It is Declare Red List Free and verified under the ICC 700 National Green Building Standard for foundation waterproofing.
DELTA-MS for New Home Construction
On new residential foundations, DELTA®-MS goes on after the forms are stripped and before backfill. It covers the wall from the footing up to the grade line. Because it's recognized under the IRC for both dampproofing and wall waterproofing, builders can use it as a single-product system instead of spray dampproofing plus a separate protection board. That means fewer trades, fewer inspections, and fewer weather delays.
Installation Requirements Buyers Should Know
These are the code-report requirements that most affect ordering and scheduling. For step-by-step installation, see our How to Install DELTA®-MS Dimpled Membrane guide.
- Dimples face the wall. The flat flange goes at the top.
- Laps: at least 6 in horizontally and vertically, dimples interlocked, with a continuous bead of DELTA®-SEALANT about ½ in wide between the laps.
- Top termination: mechanically fastened and sealed, finished with DELTA®-MOLD STRIP, DELTA®-FLASH, or DELTA®-TERMINATION BAR at 8 in on center. This keeps soil out of the air gap.
- Fasteners: nails for poured concrete and block, screws for ICF. Plan on about 75 DELTA®-FAST'ners or 100 nails per roll.
- Block walls: concrete masonry must be parged first.
- Backfill within 30 days to limit UV exposure. Use clean backfill free of rocks and debris.
- Wall height: up to 16 ft.
- Footing drain required. DELTA®-MS directs water to the perimeter drain and does not replace it.
What DELTA-MS Is Not
- Not DELTA®-MS UNDERSLAB. DELTA®-MS UNDERSLAB is a separate product that goes under slabs to control rising moisture. DELTA®-MS is for foundation walls.
- Not standalone waterproofing for IBC commercial projects under ESR-2303. On those projects, pair it with the specified waterproofing.
- Not a substitute for the footing drain.
Complete the system: DELTA®-FAST'ner, DELTA®-SEALANT, DELTA®-FLASH, DELTA®-MOLD STRIP, and DELTA®-TERMINATION BAR.
Shop all DELTA®-MS rolls and accessories →
Ordering for a large project or need spec support? Call Spycor Building Products at (843) 517-8180.
DELTA®-MS FAQ
Is DELTA®-MS a waterproofing membrane?
Under the IRC, yes. ESR-2303 recognizes DELTA®-MS as wall waterproofing in low hydrostatic pressure conditions, and as dampproofing under both the IRC and IBC. On IBC commercial projects, use it as dampproofing or as a drainage and protection layer over the specified waterproofing.
Do I need to spray dampproofing on the wall before installing DELTA®-MS?
No. DELTA®-MS is code-recognized as a standalone dampproofing material. A foundation designer may still specify a spray or sheet waterproofing underneath it, and DELTA®-MS is compatible with common spray-applied systems.
Which side of DELTA®-MS faces the foundation wall?
The dimpled side faces the wall, with the flat flange at the top. This creates the air gap that drains water to the footing.
Does DELTA®-MS need a footing drain?
Yes. DELTA®-MS channels water down to the perimeter footing drain, which must be installed to code (IRC R405 or IBC 1805.4).
Can DELTA®-MS be installed on concrete block or ICF walls?
Yes. Concrete block must be parged first. ICF walls are fastened with screws into the cross-tie flanges.
How many fasteners do I need per roll of DELTA®-MS?
About 75 DELTA®-FAST'ners or 100 mechanical fasteners (nails) per roll, based on Dörken's installation spacing.
How long can DELTA®-MS stay exposed before backfill?
Backfill within 30 days of installation to protect the membrane from prolonged UV exposure.
What's the difference between DELTA®-MS and DELTA®-MS UNDERSLAB?
DELTA®-MS is a foundation wall membrane. DELTA®-MS UNDERSLAB goes beneath concrete slabs to control rising ground moisture.
