Sash Windows In a Loft Conversion
If your planning a loft conversion in a period property it’s very likely you will have to install sash windows to match the rest of the property and there are a host of factors to take into consideration. The first scenario would be the width of opening you are granted. If we are talking about two four foot slots at either end of the room then you are likely to have single standard double glazed sash windows. In this case the first thing will be to match the detail of the sashes from the rest of your property. Sash window horns and profiles are the first thing to get right. Most sash window companies will check this for you as standard however if you supply only and have a builder fit, it has been known to be a detail omitted frequently.
If you have a an opening of around 8 feet wide you may wish to have a double sash window. What this means basically is two sash windows side by side but made in one box sash window frame. This opens up a whole host of questions. Firstly being which balance method to use. For example if you are to have springs then you can have a central mullion just two inches thick which gives the extra light over a traditional sash which would need at least seven inches of width to allow for weights. It is one of the only times I would ever advocate sash window spiral balances.
Being in the roof it’s obvious the windows will face not only the bulk of weathering but naturally will receive the least maintenance. I see this on almost every survey I carry out in London – Sash Window Condition usually worsens the higher up the building you are to go. So going back to the initial point about maintenance it’s well worth spending the extra and having a window either powder coated to give maximum protection or a high quality hardwood to help withstand the weathering if the paint work is to fail.
On installation it is key to make sure all lead flashing is fitted correctly and water tight. The window protrudes from the roof as it is making it more likely to fail from driving rain, a big mistake would be not to seal flashing well whilst you have perfect access with scaffolding. If this is not done correctly common problems include the window not only rotting much more quickly than they should but damp marks beneath the window damaging plasterboard and insulation whilst ruining the fresh decoration internally.
So in summary making sure decisions are made early on and the right materials used are vital to a trouble free dormer sash window.