Horizontal Blinds are basically Vertical Blinds but with vanes that are hung between two parellel rails with sprung loaded clips.
They can be used in dramatically reducing the heat gain through conservatory roofs or roof lights.
It is normal for the tracks to be aligned along the sides with the maximum length and for the vanes across the smaller width.
When measuring we always recommend the use of a steel tape measure and to take measurements in millimetres at three stations in either direction for width and drop.
If the blind is to be installed within a recess - to measure for the lengths of the tracks take the measurements of the longer sides and deduct 1cm from the shorter of the two lengths if they differ.
If the blind tracks are to be fitted to fixed brackets – again use the smaller of the available lengths and deduct 1cm. You will have to choose between the standard brackets ( which alllow extension of the rail between 60-108mm and which will be supplied at no additional cost) or the larger bracket which allows extension of the rail of up to 175mm at an additional cost of £5.00 per bracket. You will have to specify how many of the larger extendable brackets you require (a minimum of two is automatic) but it is recommended that rails over 175cm have three and an extra bracket is purchased for every additional metre of rail length.
Having decided the points at which the tracks are to be fixed, using either recess clips or brackets, measure between the points at three stations and take the smaller of the three measurement widths and we will calculate the exact length required for the vanes.
The minimum length for rails is 30cm and the maximum length for rails is 450cm
The minimum width for vanes is 50cm and the maximum width for the vanes is 300cm. for film materials and 200cm for the other material options.
Finally you will have to decide how you wish the control chains to be fitted and the stacking arrangements by looking at the diagram below.
You will need to decide how far below the level of the blind, the control chain and cord needs to fall to be usable but not to get in the way!
Please do bear in mind for all measurements any obstacles, such as handles, etc. that could interfere with the perfect operation of your blind.
Also consider the possible interference of the operation of the blind by windows that open inwards - it is not advisable to measure for a Recess fitting in this case.