Dear Donny

Q The top of my radiator, which has a grill on the top, and the wall above, have turned black. Can you advise?

Ms Ray Grogan, by email

A Radiators take in cold air at the bottom, and as the air heats up, it rises, taking airborne dust with it. Over time, this causes dust streaks/black marks. You can paint over them with Zinsser B.I.N stain killer paint.

Q Can you recommend a bath panel? Mine is plastic and I would like to change to wood. Jane Stewart, by email

A The key is to get a panel the same size as your existing one. When picking a wooden bath panel, it’s probably laminated MDF. These come in universal sizes so you might have to cut it to make it fit. Be sure to seal the cut – if water gets into bare MDF it will swell, expand and be ruined.

DONNY’S TOP TIP

When it snows check if it stays on your roof and does not melt. If it stays, you have nowhere for heat to escape. If the snow melts, get your attic insulated.

Q When I flush the toilet, it sounds like a ship’s horn blowing. Can you help? Rose Medows, by email

A Some places have hard water, and if left standing, it will evaporate and leave limescale which can restrict water flow. When this happens, the flush valve makes a whistle/horn noise as water passes through. Clean the flush valve or replace it for £10-£15.

Q Can I still fix fence posts into the ground in this cold weather? I want to do it while all the vegetation has died away. Peter Forrest, by email

A If the air temperature is 3C and rising, that’s the lowest temperature I’d work in with cement mortars, renders etc. If it’s 3C and dropping it’s too cold. Ideally it would be about 15C.

SEND YOUR QUESTIONS TO: diy.donny@trinitymirror.com