READER’S TOP TIP

Extractor fans don’t remove steam or smells, so they need an air inlet into the room – either through air bricks or an open window – to allow fresh air in which will help carry away any steam and smells. Q

I had the rendering on a wall replaced about 12 years ago, and since then the glass on a window below the render has become very badly marked. What would you recommend?

Sam Torrance, by email

A

I’ve removed cement stains from glass with hot soapy water and a razor glass and ceramic scraper (not the Stanley knife scraper). You can get chemicals to remove mortar stains.

Q ADo you know what I could use to paint/waterproof the veranda on my new summerhouse? John Smith, by email I always use Osmo products when doing external wood finish jobs. One Coat Only HS or Osmo Country Colour are top-quality wood finishes. Remember to read the instructions and do all your prep first.

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

Dog’s tooth violets (erythroniums) are an underrated group of plants that are as pretty as a picture and thrive in any welldrained earth that has been enriched with a generous helping of well-rotted leaf mould or multipurpose compost.

The common dog’s tooth violet has starry pink flowers and oval greeny-grey leaves that are marbled and spotted with brown. Plant them a foot apart in your chosen spot and spread a one-inch layer of chipped bark around them to show them off, seal in moisture and prevent them being splashed with mud. Equally desirable is Erythronium revolutum, especially in its form ‘White Beauty’, which has flowers that shine out of the gloom in a shady border.

With glossy green leaves and bright yellow flowers Erythronium ‘Pagoda’ grows to 10-12in and its flowers really do resemble bright yellow pagodas.

Like the other varieties it is at home in woodland or shrub borders, and will settle in and increase the size of its clumps over the years if it likes you.