work out percent of full roof

2012paddy2012

I have an extension on to my kitchen. It's about the same size as the original kitchen. It was roofed with roof tiles...built by a builder in the good times .. always leaked.
I got a roofer to replace it ..with timber ..felt ....and fully waterproof materials... reputable guy .. but I'm getting a bit of an extra premium as it's considered just as a felt roof...the issue I have is ..if it's over 20 or 25 %....I get loaded.....I have no way of working out exactly what the percent is. .is there ( an easy to use) a conversion tool or calculation I could use to try to find near enough the actual percent this extension with the felt is? It's a 3 bed semi .. standard ...as I say the area in Question...is just the original kitchen doubled in size

Thks

Paddy

Poor Uncle Tom

You need to give the overall size of the house (l x w) without the flat roof area. Then the actual flat roof area (l x w). It's then easy to work out the percentage.

If the house areas are not rectangle in shape, break them into individual rectangles.

2012paddy2012

OK thks for quick reply. So I will measure length and width of house. Then length and width of extension ...if I do that and put them here ...will you work it out for me ?!(in feet!)
Thks
Paddy

Calahonda52

2012paddy2012 wrote: »

OK thks for quick reply. So I will measure length and width of house. Then length and width of extension ...if I do that and put them here ...will you work it out for me ?!(in feet!)
Thks
Paddy

yes we will do the math if you provide the data as asked for.:)

Metric Tensor

Even better if you sketch the shape of your house on a bit of paper and post it up here. That way everyone can be sure which measurement is which.

Calahonda52

Metric Tensor wrote: »

Even better if you sketch the shape of your house on a bit of paper and post it up here. That way everyone can be sure which measurement is which.

Good idea as I suspect the math is [flat/(flat plus non flat)] *100

2012paddy2012

Hi thks for replies...just to say its a standard 3 bed semi...its 20 feet across. 28 feet in lenght.
Thats the original. The kitchen itself is ..20 x 12 feet. The extension is same as kitchen. 20 feet x12 also. The original slated roof was lean to type. Standard lean angle...I will try upload pic of it later...the roof is standard construction on the whole house except the lean to which was replaced with felt due to leakage and poor workmanship....really want to establish if its over/ ,under 20% ,if possible to say..thks

Poor Uncle Tom

So original house is 28' x 20' and the flat roof section is 20' x 12'.

Therefore the entire roof foot print is 800 sq ft and the flat roof section of that is 240 sq ft.

In this case the flat roof covers 30% of the entire roof surface.

2012paddy2012

Ah that's brilliant thank you. I said for house 30 per cent or so .. I must double check to be sure with them..I don't want to have any issues in the unlikely event of a claim thks paddy

Calahonda52

Metric Tensor wrote: »

Even better if you sketch the shape of your house on a bit of paper and post it up here. That way everyone can be sure which measurement is which.

Just to check here OP:

1. you say house is 28 by 20
2. The kitchen itself is 20 x 12 feet.
3. The extension is same as kitchen. 20 feet x12 feet

What I am not clear on is if the "kitchen itself" is included in the 28 by 20 for the house.

2012paddy2012

The original house is 20 x 28 feet.
With the extension built now the house is ..
20 x 38. (Approx) and in " feet".

Sorry for confusion.

2012paddy2012

Calahonda52 wrote:

Just to check here OP: you say house is 28 by 20The kitchen itself is 20 x 12 feet.The extension is same as kitchen. 20 feet x12 feet What I am not clear on is if the "kitchen itself" is included in the 28 by 20 for the house.

Any further views on this thanks

Calahonda52

2012paddy2012 wrote: »

Any further views on this thanks

no its works out close to what was said earlier

flat/(flat plus no flat) *100

(20*10)/((20*10)+(20*28)) * 100 = 26%

(20*12)/((20*12)+(20*28)) * 100 = 30%

exaisle

Are you quoting internal or external dimension?

2012paddy2012

External measurements..thks