How to replace a pane of glass

Clanwilliam stoep, watching the Cederberg mountains change colour as the sun sets and I write the column.

Tip of the week

I popped into a “Build It” hardware store in Vredendal over the weekend and was impressed with a stand they have at the entrance containing leaflets explaining how to do some basic DIY tasks – these are a real help to the enthusiastic but not necessarily well trained handyman. Over the next few weeks I shall pinch a few ideas from them and hopefully save you some money by assisting you in doing a couple of things yourself, instead of employing a handyman or contractor.

The first one was of some assistance to me as the sun is drying out my window frames and putty and I had to re-insert some glass.

If the glass pane is broken, you must first measure the size. Measure the rebate horizontally and vertically, and double check for squareness by measuring the diagonals, which should be the same length.

Before going to buy the new glass, make a template from stiff cardboard that fits the opening, and the glazier can use this to cut your new piece of glass.

Remember to check the thickness of the existing glass, as if you don’t match it exactly, you may end up with a problem later.

Having cleaned out the existing frame you need to insert a backing material for the putty. Always ensure the frame is primed first, as bare wood will suck the moisture out of the putty, causing it to dry too quickly and not adhere.

Personally I prefer using a clear silicone as a backing. Using a tube of silicone and an application gun, place a bead of silicone all the way around the inner corner of the rebate. Then gently push the glass into the bead, working slowly with an even pressure around the edge of the glass. Avoid pushing in the middle as this may crack the pane.

Secure the glass in place externally using two small panel pins on each side; ensure you use the correct small hammer with a narrow square edge.

Now you can apply the external putty, rather more than less initially. Once you have applied it all the way around, use a putty knife to shape it to an angle to match the other panes – keep dipping the knife into water as this not only helps smooth the putty but ensures that it seals well on to the glass.

Questions and answers

Tony is back again, with another interesting question:

I wish to have staircases built later this summer. I will be asking for three different quotes, and when discussing the project with the builders, I wish to ensure I will be speaking from a point of knowledge as to what exactly must be done.

My aim is: to build two flights of outdoor brick stairs all on virgin soil and 2 meters wide, with the initial flight being 6 steps (standard step size 240mm x 180mm), followed by a 2 metre x 2 metre cement landing and a further 6 steps. Brick walls on either side of the planned staircase are already built and stairs will be finished with black slate tiles. When requesting the builder to quote, must I ensure that the work provides for an upward-slanting concrete surface bed at the angle of the staircase? If so, should both staircases and the landing include a quote for steel welded mesh? Also, must there be any plastic damp course involved?

Answer: All too often we tend to treat garden steps as the name implies, as garden steps, forgetting that they are going to be exposed to the elements and will be carrying a fair amount of traffic. As such they must be properly constructed and protected.

The side walls should be constructed as 220mm walls on proper foundations with enough strength and bulk to ensure that they do not move or cantilever once the concrete is cast.

The ground underneath needs to be well compacted and free of builders’ rubble. Whether they are going to be constructed out of concrete or brickwork, there must be a concrete foundation, laid on a well compacted sand bed and preferably with a plastic membrane underneath. This helps not only to prevent rising damp, but will also help defeat the growth of any vegetable matter which may have been left behind.

As you already have wing walls, I would suggest that the whole staircase be built out of concrete; this will avoid the cost of having brickwork as well.

Regular readers will know that I always recommend the use of reinforcement, whether mesh or bar, in any form of concrete to be laid on built-up or even virgin ground. It helps to hold the whole thing together, if you do get erosion subsidence underneath.

It is also important to ensure that the concrete and screed are properly dry and cured before you lay the slate treads, as slate and cement tend to form efflorescence when wet, which is very unsightly. - Weekend Argus

* Keep your questions or comments coming to don@macalister.co.za or sms only to 082 446 3859.