Step 7 · Secure and Seal the Exterior Flange
Once the interior joint is fully cooled, return to the outside. Align the sillcock's mounting flange so it is level and properly oriented. Using new, corrosion-resistant screws, fasten the flange securely to the exterior wall. Use a drill or screwdriver for this. Do not overtighten, as this can crack the flange. After securing the spigot, apply a bead of exterior-grade silicone caulk around the top and sides of the flange where it meets the house siding. Leave the bottom of the flange un-caulked to allow any water that gets behind it to drain out.