Should You Replace a Carpet After Finding Carpet Moths?

The Test for Whether It Is Saveable

Look at the backing. Where the pile is thinned or grazed but the backing is intact and the carpet is sound underfoot, it is damaged rather than destroyed, and treating it stops it getting worse. That covers most cases we attend.

Where the backing is exposed over an area, or the carpet has gone through, that patch is not recoverable. But it is usually one patch under a wardrobe, and the rest of the carpet is generally fine.

Why Replacing First Is the Expensive Mistake

Fitting a new wool carpet into a room with a live population is an expensive way to feed them. Larvae in the underlay, along the gripper line and in the skirting gap are unaffected by the old carpet leaving, and they will start on the new one.

We see this two or three times every year: a carpet replaced at significant cost, damage reappearing within a year, and a treatment finally booked that could have been done first for £180.

The Underlay Question

If you are replacing, replace the underlay too. Old felt or hair underlay is itself keratin and is frequently where the population actually is — larvae feed on it from below and the carpet above shows damage late.

A modern foam or crumb underlay is not food, which is one genuine advantage of replacing properly rather than laying new carpet on old underlay to save a little.

The Right Order If You Are Replacing

Treat first. Then lift the old carpet and underlay and remove them from the property promptly, rolled and wrapped rather than dragged through the house and left on a landing. Then vacuum the bare floor thoroughly, particularly the gaps between boards and the gripper line and skirting gap.

Treat the bare floor and the perimeter before the new underlay goes down — this is the one opportunity you will get to treat the substrate directly, and it is worth taking. Then fit.

If You Are Keeping It

Treatment concentrates on the room edges and under the furniture, and is £180 for the first room and £60 for each additional one. Damaged patches under furniture can often simply be left, since nobody sees them.

For visible damage in a good carpet, a specialist carpet repairer can sometimes patch from an offcut or an unseen area such as inside a wardrobe. It is worth a phone call before writing off a carpet that is otherwise sound.