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Foundation wall penetrations
Close the gap where a pipe runs through a sleeve in a foundation wall. A Fernco reducing coupling clamps over the end of the sleeve and onto the pipe to close the gap, so soil and water don’t have an open path in along the pipe. Two clamps and a nut driver.
The job
Where a pipe passes through a foundation wall, plumbing codes typically call for a sleeve: a short piece of larger pipe set in the wall, so the wall can’t bear down on the pipe if the building settles. The model code sizes it two pipe sizes larger than the pipe (IPC 305.3) and requires the gap between them to be sealed in an approved manner with caulking, foam sealant or a gasketing system (IPC 315.1). A clamped Fernco coupling can serve as that gasketing system where your inspector accepts it.
One clamp on the sleeve, one on the pipe. The gap is closed at the end of the sleeve.
Flexible PVC, not cement or foam, so the seal takes the small movement a sleeve is there to allow.
Slide it on, push it over the sleeve, tighten two clamps. Nothing to mix, nothing to wait on.
Loosen the clamps and slide it back. Nothing to chip out if the line ever needs work.
Please check with your local inspector to confirm a coupling is an approved sleeve seal in your area.
Cutaway of a 4″ pipe through a 6″ sleeve in a 10″ foundation wall, sealed with a 1056-64 on each end. Drawn to scale.
How it works
A reducing coupling is sized for two different outside diameters. Here the larger one is the sleeve and the smaller one is the pipe running through it.
Size finder
Choose your sleeve and the pipe going through it. Or measure both outside diameters and type them in.
Measure outside diameters in inches. No calipers? Wrap a tape around the pipe and divide by 3.14.
Choose a sleeve and a pipe, and your part number shows here.
| Part | Common setup | Sleeve end O.D. | Pipe end O.D. |
|---|---|---|---|
| 1056-64 | 4″ sewer or drain in a 6″ sleeve | 6.25–6.85″ | 4.10–4.60″ |
| 1056-43 | 3″ pipe in a 4″ sleeve | 4.25–4.65″ | 3.25–3.65″ |
| 1056-42 | 2″ pipe in a 4″ sleeve | 4.00–4.50″ | 2.25–2.50″ |
| 1056-415 | 1½″ pipe in a 4″ sleeve | 4.00–4.50″ | 1.75–1.95″ |
| 1056-32 | 2″ pipe in a 3″ sleeve | 3.15–3.65″ | 2.20–2.50″ |
| 1056-315 | 1½″ pipe in a 3″ sleeve | 3.15–3.50″ | 1.65–1.95″ |
| 1056-250/150 | 1½″ pipe in a 2½″ sleeve | 2.50–3.10″ | 1.80–2.00″ |
| DTC-210* | ¾″ or 1″ plastic, or 1″ copper, in a 2″ sleeve | 2.20–2.40″ | 1.10–1.25″ |
| DTC-110* | ¾″ or 1″ plastic, or 1″ copper, in a 1½″ sleeve | 1.75–2.00″ | 1.20–1.35″ |
*DTC-110 and DTC-210 are shown with the O.D.s of the pipe they fit. Pipe O.D.s used in the finder: Schedule 40 PVC, ABS and steel (IPS), copper (CTS), no-hub cast iron (CISPI 301) and SDR-35 sewer pipe (ASTM D3034). Part numbers link to dimensional drawings.
Installation
Size it per local code, typically at least two pipe sizes larger than the pipe. Leave at least 1″ sticking out past each face of the wall.
Put it on a free end of the pipe before the pipe is joined, big end toward the wall. It won’t go on a pipe that’s already connected at both ends.
Push the big end all the way over the end of the sleeve and tighten its clamp to 60 in-lb.
Center the pipe in the sleeve and tighten the small-end clamp to 60 in-lb. Repeat on the other side of the wall.
Right tool for the job
| Product | Fernco 1056 series reducing couplings and Drain & Trap Connectors (DTC-110, DTC-210), used as sleeve seals |
| Body | Flexible PVC |
| Clamps | 300 series stainless steel, two per coupling |
| Installation torque | 60 in-lb |
| Temperature | −30°F to 140°F intermittent, 120°F continuous |
| Standards | Couplings comply with ASTM D5926, C1173 and CSA B602 |
| Maximum test pressure | 4.3 psi, as a pipe coupling. Not rated as a hydrostatic sleeve seal. The pipe carries any line pressure, not the coupling. |
| Made in | USA. AIS and BABA compliant. |
The catalog page and a dimensional drawing for each coupling.
Usually, yes. The model plumbing code calls for either a relieving arch or a sleeve two pipe sizes larger than the pipe where a pipe passes through a foundation wall (IPC 305.3). Local codes vary, so check with your inspector.
The model code says the space between the pipe and the sleeve is sealed in an approved manner with caulking, foam sealant or a gasketing system (IPC 315.1). A clamped coupling can qualify as a gasketing system. Your local inspector makes the final call.
No. The coupling is a solid ring, so it has to slide on from a free end of the pipe. On new work, put it on before the pipe is joined. On an existing line you’d need to open the line to fit it.
Use a DTC-110 in a 1½″ sleeve or a DTC-210 in a 2″ sleeve. Both fit ¾″ or 1″ plastic pipe in IPS sizes (1.05″ to 1.32″ O.D.), or 1″ copper.
In 1″, the DTC-110 and DTC-210 fit 1″ copper. Most larger copper sizes are smaller on the outside than plastic or cast iron of the same size, so they fall below these couplings’ pipe-end ranges. Measure the O.D. and use the finder.
The couplings are rated for gravity drain lines, with a maximum test pressure of 4.3 psi, and haven’t been rated as a hydrostatic sleeve seal. Where the water table is high or the spec calls for a rated sleeve seal, use one.
The coupling needs at least 1″ of sleeve to clamp to. If the sleeve doesn’t stick out, a coupling won’t work; use a seal made to fit inside the gap instead.
Whether it’s sizing, an odd fitting or a tricky tie-in, our team can help. Reach out, or find your Fernco rep.