Calculating flat roof percentage for insurance purposes

sarkozy

A policy we wish to take out specifies that we can have a percentage of the roof as a flat roof at no more than 25%.

I just want to check how this is calculated. I've checked the room dimensions up and down, left and right, and I can't get anywhere near the threshold, but I'm nervous. Here's what I did.

Drew a floor-plan of the upper floor including the flat-roofed return. Entered in the room dimensions (since the hallway/staircase dimensions were absent, I inferred this from dimensions and arrangement of the rooms of the house proper. Added up the lengths on two sides and multiplied to get the area of the house proper. Then I got the area of the return. Then I added those two figures together. Then I worked out the percentage of the return's roof area against the total roof area (house proper plus return).

For safety, I tested the dimensions here and there and have not managed to exceed 22%.

Is this the correct way to go about it?

I realise that if I actually factor in the pitch of the main roof and work out that area, the roof area is even bigger and the flat-roof percentage even less.

It's weird, because looking at the house physically, it looks more like 25-30%.

fasttalkerchat

sarkozy wrote: »

A policy we wish to take out specifies that we can have a percentage of the roof as a flat roof at no more than 25%.

I just want to check how this is calculated. I've checked the room dimensions up and down, left and right, and I can't get anywhere near the threshold, but I'm nervous. Here's what I did.

Drew a floor-plan of the upper floor including the flat-roofed return. Entered in the room dimensions (since the hallway/staircase dimensions were absent, I inferred this from dimensions and arrangement of the rooms of the house proper. Added up the lengths on two sides and multiplied to get the area of the house proper. Then I got the area of the return. Then I added those two figures together. Then I worked out the percentage of the return's roof area against the total roof area (house proper plus return).

For safety, I tested the dimensions here and there and have not managed to exceed 22%.

Is this the correct way to go about it?

I realise that if I actually factor in the pitch of the main roof and work out that area, the roof area is even bigger and the flat-roof percentage even less.

It's weird, because looking at the house physically, it looks more like 25-30%.

I'm finding it hard to picture. Can you find it on google maps or streetview?

sarkozy

fasttalkerchat wrote: »

I'm finding it hard to picture. Can you find it on google maps or streetview?

No, like, I'm describing the method. I mean, basically, I sketched the floorplan, entered in the room dimensions, got the total floor area, then got the flat roof area as a percentage of the total (incl. flat roof area).

It makes sense to me, but I need to confirm!

fasttalkerchat

sarkozy wrote: »

No, like, I'm describing the method. I mean, basically, I sketched the floorplan, entered in the room dimensions, got the total floor area, then got the flat roof area as a percentage of the total (incl. flat roof area).

It makes sense to me, but I need to confirm!

That sounds about right but it isn't very accurate. If you are coming to 22% and the limit is 25% that is a fairly tight margin. Have you accounted for where the roof overlaps the exterior walls?

kkelliher

if your main roof is sloped then the actual roof area will be bigger than the plan size of your floor area.

Generally if you have worked out your floor area in total you just devide the area of flat into it and you should be there or there abouts. If you are close to the margin remember the sloped area will be more and in any event unless you are above the % the insurance company are not going to have an issue. Its more important to comply with their wordings in respect to bi annual or tri annual maintenance.

sarkozy

kkelliher wrote: »

if your main roof is sloped then the actual roof area will be bigger than the plan size of your floor area.

Generally if you have worked out your floor area in total you just devide the area of flat into it and you should be there or there abouts. If you are close to the margin remember the sloped area will be more and in any event unless you are above the % the insurance company are not going to have an issue. Its more important to comply with their wordings in respect to bi annual or tri annual maintenance.

I did work out the sloped roof area and it is, indeed, bigger. I'll double-check this with someone I know in the construction sector. Thanks. I just needed this to rest at ease.

roof?

Looking for info for long time on this - just one thing - can anyone tell me very simply how to measure a roof for insurance purposes. I have a flat roof extension which I need to know % of overall for. The house is end of terrace which gives three sides to get measurement for. I can do the wall to wall stuff but haven't a clue about pitch. Can anyone tell me how to allow for that please?