Look, he got another question

I got two garagedoors (the type that slides upp and under the roof).

Naturally I want to put a pair of magnetic contacts there so that the alarm can cover them.

Will it do with standard "long reach" contacts like SQR 550? http://www.securitywarehouse.co.uk/catalog/index.php?main_page=product_info&products_id=393

Installing 200 computers in one day is easy, this is hard

Lol. You need to be careful with contact placement on those types of doors do to the play in the door when locked. 2 places are commonly used for fitting. 1 id adjacent to the spring lock, the other is below the sliding mech.

If there is not much play then yes a contact like the 550 will be fine. The roller shutter type usually have more range to allow for a little play in thte door.

I assume GRP sectional door ?

even though your "IT" I'll be nice & say you take a piccy & I (we) will tell you what & where.....

Be careful if using the floor mounted type, that they don't lay in puddles during/afte rain. Water will often seep in and cause corrosioon problems later, so best avoided.

Check to see where the shutter tends to stop naturally in the runners,, run it several times, marking as you go, then centre on the most common place.

Arfur

Edited October 25, 201015 yr by arfur mo

This type of door also "woobles" a lot. Due to its construction.

A good idea is to insert a piece of wood into the edge of the door and fit the contat to that.

Two fold, 1 it is more stable. 2, the fixing screws are not visible from outside.

Encapsulated contacts will live in a moisture enviroment.

Edited October 25, 201015 yr by Oxo

I'm a little worried about the play of the door, I dont think it's more than a cm sideways (rather new door and a tight fitting to get it in. They claim that the 550 can do 30 mm gaps.

Using the latch fastening is a very good idea, thanks for that one

I ruled out the floor mounted type. I doubt that snow and ice will benefit the function of the contact. And yes there will be snow and ice in a few weeks

could use ali with 50mm gap

http://www.cqr.co.uk/en/product-catalogue/magnetic-contacts/grade-2/gp001-heavy-duty-contacts.aspx