Cat6 and Pull String in House-Side SLS Junction Box
Photo Details
- Date: April 19, 2026
- Time: 5:17 PM EDT
- Weather: Spring conditions (dry ground, bare-earth backfill visible); specific observations unavailable from nearest NOAA station.
- Phase: Interior network — owner DIY cable pull
- Location: 309 E. 7th St., Clare, MI — NW corner of house, exterior junction box
- View: Close-up into the open house-side PVC LB/extension box
Description
House-side terminus of the new Cat6 run that powers the garage Ubiquiti U6+ access point. Shows the owner-pulled Cat6 (white jacket, curling up out of the conduit) and the pull string left in place for future cable additions, both emerging from one of the two 1” PVC conduits SLS Electric installed as part of the underground feeder scope (see the March 31 photo of this same corner for the conduit run context and full route overview).
The second conduit (visible at right edge of the photo) is still empty — the dedicated spare for the planned 10GbE fiber run. From here the Cat6 drops down through the conduit, runs underground to the garage, terminates at the server rack indoors on the house side, and on the garage end feeds the U6+ AP via PoE (commissioned April 22).
Visible Elements
- Gray PVC exterior junction box (LB-style extension / weatherproof device box), wall-mounted on white lap siding
- White Cat6 cable looped inside the box, emerging from the conduit below
- Twisted white pull string (polypropylene/jute style) left in the conduit for future pulls
- Two 1” PVC conduit stubs entering the box from below
- Second adjacent gray conduit body visible to the right — the spare (future fiber) run
- Ground conditions: bare earth / gravel, early spring; no snow
- Visible gap between the box and the siding, with a trace of SLS’s interior spray foam protruding at the top of the near conduit body (air seal was done from inside — exterior is still open)
Follow-Up: Exterior Penetration Sealing
The interior air seal is already done (SLS sprayed foam at the basement penetrations of these conduits — see basement penetrations photo). The exterior gap around this box and its neighbor is still open and needs to be sealed by the owner to prevent driving rain from being forced behind the lap siding.
Approach: 3-sided caulk (top and both sides only, leave the bottom open).
Sealing all four sides creates a water trap behind the box — any incidental moisture that gets behind the box or siding loses its escape path. The bottom edge must remain open so water can drain out. The interior spray foam already handles the primary air seal at the conduit penetration, so the exterior bead’s job is narrowly about blocking wind-driven rain at the top and sides. This is a pragmatic retrofit drainage detail, not a substitute for a properly flashed mounting block integrated to the hidden WRB.
Sealant selection (paintable, flexes with vinyl-to-PVC movement):
- OSI Quad Max (hybrid polymer) — top choice, white color-matches siding
- Sashco Big Stretch (acrylic elastomer) — easier cleanup, also paintable
- DAP Dynaflex Ultra — budget option
Avoid pure silicone (won’t bond reliably to vinyl, not paintable) and plain acrylic latex (won’t hold up on a joint that moves).
Procedure:
- Trim the excess interior foam flush to the box/siding with a utility knife once cured
- Wipe the joint with denatured alcohol, let dry
- Apply a shallow surface bead across the top and down both sides of the box-to-siding joint
- Tool the bead with a wet finger for a clean profile
- Do not pack the cavity full or try to reach a hidden vapor barrier; the sealant only needs to bond to the exposed box and siding
- Leave the bottom edge unsealed to allow drainage
- Apply the same treatment to the adjacent gray conduit body visible at right (same SLS run)
Why not a siding mounting block? That would have been the ideal install — a flanged block (Arlington InBox, TAPCO) set under the siding course before the box was mounted, giving a flat surface and proper flashing. Retrofitting one now means pulling siding courses, so 3-sided caulk is the pragmatic answer at this stage.
See Electrical Planning — Exterior Penetration Sealing for the full write-up covering all SLS-installed exterior boxes (this one, the adjacent fiber/spare box, and the NW corner 50A generator inlet / GFCI outlet).