The problem
A recurring problem with the spike attached rain gutters is their sagging and pulling away from the boards they are nailed to. This problem must be repaired fairly quickly so the guttering will carry the rain water away from the house or building before any lack-of-drainage damage happens to it.
This problem happens most often to the seamless guttering that has been rapidly spike-nailed to its adjoining fascia boards and underlying rafter ends instead of being attached to them with wrap-around clamps or long screws. These so-called spike-nails, which are also guided through cylindrical spacer tubes (called ferrules) to keep the gutter width even, give the guttering a clean smooth appearance when its installation is done. However, over time this nail-to-wood attachment loosens under the varied weather conditions (dampness, ice, snow) and the weight of the rain water itself. The gutter then sags or pulls away from the eaves. Numerous ways to fix this problem have been suggested, everything from stuffing the spike holes with splinters of wood to using epoxy glue in them. However, two ways to fix this problem with long screws are listed below.
Fix 1 — replace the gutter spike-nail with a gutter screw.
A standard and straightforward fix is to replace the spike-nails with a gutter screws, which can be purchased in packages of 10 at local hardware stores for about $10. These gutter screws are the same 7″ length as the common spike-nails used on home guttering, but their threaded portion is slightly wider than the body of the spike itself. These screws have thin flat heads similar to those of the spike-nails. However, they will not take a typical screwdriver bit. Instead, they have sunken square sockets that must be turned with a square driver-bit that comes with the package. These sockets are also left unpainted so the driver-bit will fit into them properly. Thus, for a smooth final appearance, these sockets could need touch-up painting when the replacements are done.
Also, since the threaded portion of these gutter screws are only slightly thicker the spike-nails, they will not take secure bites into the fascia boards if the original spike holes are dry rotting or enlarged for any reason. For that reason, the gutter screws might not hold the guttering in place for long. These holes can be examined before purchasing the gutter screws. If they look soft or enlarged, the following alternate fix might be preferred to the gutter screw.
Fix 2 — replace the gutter spike-nail with a sizable lag-screw.
A second and possibly better fix is to replace the spikes with 5/16-to-3/8″ lag-screws that are the same lengths as the original spikes. For residential guttering (4-5″ wide) that length is about 7″. For large barns, warehouses, and certain commercial buildings having larger guttering (6-7″) that length will be close to the length of the original spikes used on that guttering, about 8″ or so. These relatively thick and sturdy threaded lag-screws will take secure bites into the fascia-board holes even if they are slightly worn. These lag-screws will also fit through the original ferrule spacers fairly well, and they are easily screwed into place with ordinary ratchets or wrenches. Lag-screws of all lengths can be obtained at hardware stores.
Generally, the functionality of the larger (6-7″) gutters is more important than their having final smooth appearances. Thus, the raised hexagonal head shapes of the installed unpainted lag-screws is not an issue most of the time. Still, they can be touched-up with matching paint if desired after the gutter reattachment is done.