Irrespective of the size of your chosen Spacetwo garden room, granny annexe or extension it’s important to decide on the type of roof construction you would prefer. This decision can affect many aspects of the buildings design and the construction methods used so will also influence the price. We use two types of roof design, flat or pitched.
As it states its flat, well almost. All flat roofs require a “fall” to help shed water, which is recommended by building regulations as a minimum of 1:40. This means for every 40 units horizontally the roof should fall by 1 unit. So, for a metre in length the roof will fall by 25mm. Flat roofs are the type most commonly used in garden rooms.
Advantages of a flat roof:
- Less complicated to design so therefore cheaper.
- Generally, less complicated to construct so therefore cheaper.
- Don’t need as much vertical height so can keep a building within permitted development rules
- Easier to maintain as access to the roof is much simpler (you can walk directly on the roof covering)
- You can utilise the flat surface to carry a green roof (usually sedum), but this will require modifications in roof design to carry the extra weight
Disadvantages of a flat roof:
- Less attractive than a pitch roof due to the roof covering used (generally EPDM rubber). However, this can be overcome by installing a green roof covering.
- Prone to failing if poorly installed.
- Require more maintenance
- Suffer from U.V. Degradation
- Life span is usually 20 years, which is not as good as most pitched roofs
A pitch roof is defined as any roof with a slope of over 10 degrees. This type of roof is less commonly used in garden rooms but at Space Two we offer both types as part of our design and construction service.
Advantages of a pitch roof:
- More attractive than a flat roof
- The roof void can be used as extra storage or to include more insulation or as a vaulted ceiling, greater room height.
- Better weather resistance
- Better lifespan than a flat roof
- Generally require less maintenance
Disadvantages of a pitch roof:
- More complex to construct so therefore can be more expensive
- Usually requires a covering of shingles, slates or some similar material which again adds cost and complexity to the build
- More difficult to maintain if any problems arise
- Requires more height, so the building is less likely to fall under permitted development
- Can put a greater weight on footings
So there are pros and cons with each type of roof but whatever type of design you choose, here at spacetwo we will be happy to guide you through the design process to ensure the choice you do make is an informed one.