Alright, I know these products.

My concerns are:

- The product is rated IP55, may not be water/dust proof for outdoor use over a long period of time.
- It says it has 4 beams, but did not say how the 4 beams are positioned.
- Immunity against direct sunlight. Not sure if they will have intermittent problem or not if the receiver is directly against the sunlight.

soory my sensor suggestion was for bungalow. for link house of course have to somehow secure the link parts to. not too sure what to do there but a beam shooting from top of roof down might be a good idea.

I think put in the zink plate or grill will be more reliable.

Because when the thief saw that thing also lazy to come in, because need to take more time to break in and some more if want to break the zink plate or grill will need to bring up more toots to cut it, while they cutting it, I think nearly 2 or 3 of your surround neighbor also can hear it. So mostly they will give up.Some more if you put in an extra detector I think while they cutting also will trigger the alarm already.

Unless the thief very canggih and bring up the laser cutter or welding machine to cut it, then it will be not much sound creating but still need to go through the final trigger. So I think put up this 2 item is safe enough

The 4 beams position wise actually is up to you to position as long as there is no blocking in between, even if u put it at 45 degree angle it still work as long as both beam signal are connected. As for the other 2 points can't comment now only time will tell, lucky at the back of my house most of the time the direct sun light don't stay too long.

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Added on February 19, 2010, 6:38 pmits a good idea but u might need a very very strong spot-light to do that.

This post has been edited by Tohsan: Feb 19 2010, 06:38 PM

the grill idea is pretty good and practical

how much does it cost ? can use the hollow type or my use solid ones ?

Tohsan,

i think a PVR beam with a good range should do the trick if you have a per-safe one. we secured the entire house's perimeter like that. so before you can place a ladder to the roof you trigger alarm already. you approach the doors or windows - also alarm is off already. can even set alarm to call police and play pre-recorded distress message which is pretty neat. and those pet-safe sensors (once fine-tuned) hardly ever produce false alarms and are totally weather proof. range is probably around 20 m in both directions from the PVR. i'm quite happy with them. but for the roof one probably would have to cover/close one side so it doesnt shoot into the air.

brotan,
if you want to use grill better get a good (i.e. solid) one. the more work you create the better your neighbour's place will look to a thief

You may refer to to this:

http://forum.lowyat.net/topic/1016556/+1900

i am staying in terrace house corner lot

i personally went up the roof of my house
its actually kinda big space which defintely can make rooms out of it

but for what i did, i diy by adding extra woods which make movement is impossible for a person to go thru. i also lay nails penetrating out, shattered glasses on the roof floor

but once i do hear heavy bangs, heavy walks on the roof, climb up and checked ... nothing there

nothing loss in my house anyway

but how much would it cost for the grill per sq feet ?

brotan,

not too sure. you should check with your contractor to get an estimation. we did it with a complete house-redo and got it at a very low price as extra benefit of some sort. but the roof area to close was huge (over 3000 sqft) so i dont think my pricing would be too helpfull. if you really need i can look up the cost in my expense sheet. i think i still have the number somewhere.

I also not sure about the price, because I am waiting my house to collect the the key and then I will look for those grill contractor look for their opinion.I think is not cheap also, because the roof top is very huge and big. hehe

But I also think of putting the zink plate, because it can reduce heat from the roof and actually is very hard to break the zink plate also. once you touch it sure got sound come out and very loud also. If want to safe cost abit I think also can add extra wood in between, so just make the hole small enough and can't go through. Unless they bring the saw to cut it, but very loud and waste a lot of time also. While they cutting it, I think you have enough time tp make a call to 999 already

1st golden rule.... never ask serious question in kopitiam... if you plan to get silly answer & stupid yet spamming post, go there

I did this on my house ........ DS... since I`m selling building materials, so I use this and ask the welder to weld it on top of the roof....

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Added on February 22, 2010, 5:41 pmP/S.... latest news from my customers.... now thief are using car jet to jet open the grill rather than saw/cutter

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Added on February 22, 2010, 5:44 pmcorrection... zinc plate are good heat conductors......

This post has been edited by Awakened_Angel: Feb 22 2010, 05:44 PM

what is that ?

ya they do use car jack nowadays to pry open window grill, tat will happen if the distance between the grill pattern is "wide" enough for the car jack to fit in otherwise it will be difficult a bit. Thats why I opt for Barrier Sensor, u tresspass oni the alarm will trigger without any knocking or hacking at all.

If its a landed property
Like my house , install a layer of zink before installing the ceiling

i think the best and most economical way is to install barb wire on the roof there + the wire mesh as show by one of the posters.

Based on family member experiences, true for USJ 13, 11, 2 ESPECIALLY and 9. Not sure for other parts of usj.

makesure after u put up those bard wire in the roof when u want to do something up the roof, don't step into those wire and get "trap" by it. My old house use to put these too but the "smart thief" still able to escape those bard wire n ransact the whole house, and escape back thru the roof.

This post has been edited by Tohsan: Feb 24 2010, 02:17 PM

hmmm smart thief.. that is one that i had not encountered before... maybe the barb wire is not properly set kua... yea i will bear in mind to bring my spot light up when i'm going to do some work up there..

heard from a friend he and his uncle used to rig their roof with barb wire and then hook it to the electricity pole outside.- street light pole to be more exact... i wonder would it actually work ... its like having an electric fence in the roof.

Those "electric fence" in the roof thing got one case in Sabah, one thief was killed when try to break-in, the death body was stuck to the electric fence until the owner come back.