Surveyors and structural engineers utilise data from tables below to help calculate the correct size strength and centres of roof timbers for the required spans and loadings.
Hip roof timber sizes.
Enter the extension wall length into wall length and double the extension wall width then minus ridge thickness into the wall width entries.
Automatically calculate suitable rafter sizes enter a specific rafter size 1 3 timber strength.
Pitched roof timber sizes.
Imposed loads roof snow load and short term point load altitude not exceeding 100m.
The best way to transfer load is with a timber to timber joint a compression fixing.
Structural calculations for timber joists timber beams glulam beams flitch beams using the latest design codes.
All the figures are based on roofing tiles or slates laid on timber laths over sarking felt.
When rafter spans are too great a purlin is introduced to break the span by transferring the loads to gable walls or in this case to the hip rafters.
This table is considerably more useful that the one that was in the previous 1990 edition of the regulations as not only maximum truss spans are indicated but also the allowable and recommended pitch of the roof and the member sizes and grades of timber that are specified in sans 1783 2.
Now the engineer has specified that the new hip rafters on the back need to be 12 x2 and yet the roof will not be taking any etra load in that area this is proving troublesome as i cannot gey timber that size and will also cause me problems with boarding out the corners.
For many people being able to get the right kind of hip roof calculator is very important as knowing how to measure a hip roof is going to be vital to making sure that it turns out well.
Enter the extension wall length into wall length and double the extension wall width then minus ridge thickness into the wall width entries.
This calculator will help you estimate hip roof parameters including rafters and roof area person outline anton schedule 2011 08 29 17 53 20 one of users asked us to create calculator which will help him estimate hip roof parameters like rafter s lengths roof rise and roof area.
For pitched roofs flat roofs and ceiling joists.
Surveyors span tables for designing roof rafters.
Minus ridge thickness to allow for ridge becoming pole plate roof peak will be slightly higher ridge thick must be same.
My existing hip rafters are 5 x1 5 and approx 7m long.
Minus ridge thickness to allow for ridge becoming pole plate roof peak will be slightly higher ridge thick must be same.
If you are trying to undertake this all yourself then you should really be looking for the most effective way of working out things like the hip roof square.
Porch roof extensions for hip roof porch extensions from an existing building wall you can use half the calculator results.
Nails bolts and screws create a mechanical fixing to stop uplift through wind etc.