client wants overkill on lightning protection

chris- · May 15, 2012

client wants overkill on lightning protection. i undertstand that all of the top peaks of a building should be covered by this lightning tape and down into an earthrod but this clients architect wants top ridge covered ( understandable ) but then wants tape all along the gable roof zig zagging all the way up and down the roof and then 5 yes 5 earth rods. to me this is overkill big time. i cant seem to find the bs en 63205 reg can someone advise please

chris- · May 15, 2012

there are 10 gable peaks on the building

sedgy34 · May 15, 2012

ive been here before also, its not a requirment just recomended for lighning protection
you should gladly quote him he will decide aganist it when he see the price.

Engineer54 · May 15, 2012

Well i can tell you that you never zig zag LP tape or cable, as any angles must never be less than 90 degrees due to flash overs... All tape and cable runs should ideally be in straight horizontal or vertical lines. Sometimes if low dividing upstand walls are less than 4'' wide, it's better to drill and pass the LP through, rather than go up over and down the other side. As a lightning strike can take out that bit of brickwork between the conductors on either side!! lol!!

So whats the building and the overall length of the building?? 5 earth electrodes seem to be on the low side to me as you require a down conductor every 10 metres on each side of the protected building

chris- · May 15, 2012

the building is shaped like quarter of a pie on the corner of a street, he proberbly has it right at every 10m then. its timber fram student diggs

Engineer54 · May 15, 2012

How many stories is this building and are there any substantially higher buildings in it's vicinity?? Come to that has a risk assessment been made, as to this buildings requirement for a lightning protection system??

I really don't know why Architects get involved with LP systems, as people like Furse will design a LP system for clients, hoping to sell there well known and respected materials for the installation. Bloody good service it is too, all their designs come with a fully detailed material take off, ..obviously based on their products!! ...lol!!