The main points of difference between a Quality Built Sunroom and a cheap one are;-
- Windows resting on the roof with no masonry between roof & top of windows. This means there is a very light roof on the sunroom usually a type of tiling cladding, the cavity in this roof is not adequate for the thick 125mm or 150mm Kingspan roof insulation to create a warm cosy room.
- Sometimes with these cladded roofs the pitch is quite low i.e the angle of the roof. With the low pitch roof it is not possible to put roof windows in as these will leak if the pitch is below 18˚. Roof windows are not just important for getting light back into the new sunroom but also to get light back into the original house usually the kitchen/dining area.
- On the cheaper version, usually if there is an Apex window, the glass will run uninterrupted under the angle of the roof but with the better version will show approximately 300 mm of masonry under the roof on top of the Apex window and masonry running across at wall plate level usually just over the doors – structurally this is a much better option. The apex window will usually be split in the centre by a pier which will help carry the weight down off the roof from the ridge.
- One of the main features of the sunroom is the high ceiling, creating a feeling of space. However, this can lead to problems if it is not done properly especially on wider rooms that are the full width of the house e.g. a 3 or 4 bed semi aprox. 20ft-22ft because to create this high ceiling there is no ceiling joist. The ceiling joist helps to keep the roof together structurally as there is a lot of outward push on the side wall from the roof created by a couple of tonnes in weight from all the roof timbers & tiles. When we get a heavy snow fall which is now quite common the weight can double with a couple of feet of snow on the roof and without the aid of joists all this weight is putting pressure on the two side walls of the sunroom. In a worst case scenario it could cause the walls to push out.
So what should be done to counteract this?
- There should be a Ring beam all the way around the sunroom or a Steel beam & this should also be tied back into the house & the roof should be bolted down into this beam.
- Heavy roof timbers should be used 7 x 2 or 9 x 2 if the width is over 20 feet. The centre of the roof timber i.e. the distance apart should be no more than 200mm.
- There should be twisted wall-plates aprox. 1.5 meters long tied into the rafters & not on the wall plate helping spread the weight of the roof further down the wall & taking some pressure off the top part of the wall. The roof timber should be doubled around roof lights.
- If the roof is Apex styled usually with a glass to the rear the Apex should be split in the centre by a pier, this pier carries some of the weight of the roof usually down to a concrete beam or RSJ which sits just above the door height.
A lot of the above points on the roof go back to our original point of having the roof resting on the windows or the Apex glass running right up to the roof and not split by a structural pier both of which don’t look particularly good either but if this is the case the chances are the room is structurally very poor.
Show the masonry over the Apex windows under the roof + on the pier that splits the window in half for a good look and to the give the room a look of uniformity.
The masonry example we are describing can be seen on the Arkwood website. Contact us to find out more.