Screens, Foam and Brush Guards

Drop-in plastic and wire screen

This is the guard most people have already met. A length of curved plastic or coated wire mesh, bought by the foot, bowed into the trough so that it presses against the front lip and the back. It goes in without tools. That is the entire proposition and it is not a bad one at the price.

It stops what it says it stops. Whole leaves, twigs, a tennis ball, a squirrel. It does not stop maple seed, it does not stop grit and it certainly does not stop pollen, so the gutter underneath keeps accumulating a fine layer of sediment that eventually finds the outlet. You are still cleaning. You are cleaning less often and with less unpleasantness, which for a small house may be exactly the right trade.

The failure is mechanical and it is predictable. A drop-in screen is held in place by its own springiness and nothing else. Load it with a mat of soaked oak leaf and the weight bows it downward. Freeze that mat solid and the ice, which is bigger than the water was, pushes outward against the lip. Do that a dozen times over a single Missouri winter and the section walks itself off the gutter. By March it is either hanging down the fascia or lying in the flowerbed.

Foam inserts

A foam insert is a triangular wedge of open cell foam pushed down into the gutter so that the trough is no longer an open channel. Water is meant to soak through the foam and run away underneath. Leaves are meant to sit on top and blow off.

For one season, on a house with light debris, that is roughly what happens. Then the foam does what open cell foam does in a wet outdoor environment. Fine sediment washes in and stays. Pollen, grit and shingle dust bind into a crust on the upper surface. The foam holds moisture between rains instead of drying out, and in a St. Louis July an object that is permanently damp, organically loaded and sitting in full sun grows things. Moss and seedlings in a foam insert are not a freak occurrence, they are the normal end state.

The part rarely mentioned at the point of sale is removal. A saturated foam insert that has been in a gutter for several summers has to be pulled out in pieces, and it comes out heavier, dirtier and more fragile than it went in. That is a worse afternoon than the gutter cleaning it was bought to avoid.

Brush inserts

A brush insert is a long cylindrical bottle brush laid along the gutter. Debris is supposed to rest up on the bristle tips while water finds its way through the middle. It is quick to fit, it costs little, and it does keep large leaves off the bottom of the trough.

The trouble is that the local debris is exactly the wrong shape. Maple samaras are thin, stiff and pointed, and they thread into a bristle brush and stay threaded. Pine needles do the same thing more efficiently. Oak catkins wrap. What accumulates is not sitting on top of the brush where rain can move it, it is inside the brush, woven through the bristles, and the only way it comes out is by pulling the whole brush from the gutter and shaking it.

At that point the brush has become the clog. A gutter with a fouled brush in it is harder to clear than a gutter with nothing in it at all, because the debris and the tool are now one object.

The honest summary

• Drop-in screen. Reasonable value on a low, reachable run, if you accept that it will need putting back and that fine material still gets through.
• Foam. Hard to recommend anywhere with real tree cover. The failure is slow, invisible from the ground and unpleasant to reverse.
• Brush. Wrong shape for the debris this region actually produces. Fine under a broadleaf with no seed and no needles, which is not most St. Louis lots.

None of these three is a scandal. They are cheap products doing cheap product things. The mistake is buying one expecting the outcome that is advertised for a fitted guard, and the pitch that blurs that distinction is covered on the sales pitch page.