Should minidishes go on chimneys?

Milktrolley

Had Sky installed in April 2000. At the time, we were told that it was dangerous to put dishes on chimneys, as winds would be stronger and damage to the dish more likely. The dish was put on the front of the house, just above the first floor. Our home is semi-detached, so we don't have a right-hand side as such - which would be the ideal place from which to aim at 28 degrees East.

Anyway, today I was told by a local engineer that there's no problem putting dishes on chimneys, and that anyone who says otherwise can't be bothered climbing up and going to that much effort. Currently, we receive 85% Signal Strength and 50% Quality. I would greatly assume that this would improve were the dish on the chimney.

Our dish is acting up at the moment (we still have the channels ) and we're getting it repaired by that engineer next week. My questions to you, dear reader, are: would we be best to leave it where it is, or move it up to the chimney? Are there any significant pros and cons to consider?

Thanks for reading

Tony

ask this so called "engineer" how he intends fixing the dish to the chimney, if he intends using anything other than a lashing kit then I would re consider using him. Dishes are not installed on chimneys for very sound reasons nothing to do with "being lazy". Why not put the dish on the back of the house using a pole and stand off bracket?

cast_iron

Well the chimney will be a windier spot than down on the front wall. Common sense will tell you that. Also, you'd be surprised at the amount of loose chimneys on houses these days - building regs state that the chimney top actually can't be cemented to the rest of the chimney.

So, the advice was correct - in theory, at least. Though it's not usually such a critical problem. Odds are, it was put up on the front of the house due to laziness. It's much easier to put it there, though quite how you allowed it is beyond me - it's illegal and one hell of an eyesore.

I wouldn't advise moving a 6 yo mini-dish, between rust and poor build quality - it'll never go up right again.

Trevord

Another issue is a structural one. While your chimney may never fall off, with a dish on it, you may, if unlucky, get some cracking on the chimney (due to stress on chimney from winds) which can lead to dampness getting in, especially if it happens around the base of the chimney.

Same is true for MMDS ariels, where the pole is longer than neccessary (which seems to often be at the whim of the installer) you can get a law of the lever type thing in operation.

Finally, depending on which county you live in, dishes on chimneys are also in breech of planning as they are above gable height (but same is true if on the front of the house!).... although like so much else in this country you'd have to be unlucky to be hauled up on that.

See point 12

http://www.galway.ie/en/Services/Planning/MakingaPlanningApplication/Doingworkaroundthehouse/

Berberis

cast_iron wrote:

building regs state that the chimney top actually can't be cemented to the rest of the chimney.
.

What are they building chimney's in your area out of? LEGO!:eek:
Chimney cappings have always been beded on to chimney with a a cement mortar mix. (I should know I've been building them for years)
As for attaching dishes / poles etc I personally would not recomend it as the vibrations of the dish/pole moving in bad weather will eventually weaken the structure of the chimney stack itself, which will cost far more to repair than a dish.

Milktrolley

Just to clarify, the dish is only three months old as it was replaced back in September.

We'll definitely take this opportunity to move it off the front of the house - in hindsight, allowing that to happen was far from the best thing to do. Fixing it directly onto the back of the house isn't an option unfortunately. As suggested earlier, how about a pole and a stand off bracket at the back of the house? Best thing to do?

byte

Bear in mind that the installer will be coming to fix the problem, and not to move it to another part of the house.

But if you are to move it, then the stand-off brackets and pole mentioned by Tony would be the best way around the situation.

ixtlan

People might remember me as "paranoid chimney guy".

Some time ago I started a thread very similiar to this one. Anyhow my dish remains on my chimney, though every storm sends a shiver down my spine in more ways than one!

I now realise that dishes should not be installed on chinmeys. In the next few months I intend to get SkyHD, and I'm hoping to have the dish moved to a standoff brackett at the rear of the house... or more accurately have a new dish installed. The existing one is far too rusty.

Remember with the standoff brackett that if you have a low-pitch roof the dish should only need to be 30cm above the gutter as the satellite is approx 30deg above the horizon.

Ix.

Milktrolley

byte wrote:

Bear in mind that the installer will be coming to fix the problem, and not to move it to another part of the house.

But if you are to move it, then the stand-off brackets and pole mentioned by Tony would be the best way around the situation.

Some of the bolts have become loose as a result of the recent storms. I've tightened them, but this is only a temporary measure as the fixings which attach the dish to the wall have become damaged, so need to be sorted out. He called around today and found that I had tended to the problem, for the short-term anyway, and he'll be calling around again towards the end of next week. He has offered to move it up to the chimney - I figure that if he's willing to do that, he'll have no problem moving it to the back of the house.

What problems, legal or otherwise, would be associated with the stand-off bracket? Would it be more susceptible to being moved about during storms?

Ronan|Raven

What the christ sort of bolts are they using? It is what, an 80cm meshdish? 60cm? Are the bolts made out of .5mm wire? I ask this as I cant understand how even with decent storms the bolts can come so badly out. I have a 1metre solid dish and an 80cm solid dish all hanging from one decent pole and t and K bracketing and it hsnt budged one mm in all the storms.

cast_iron

Berberis wrote:

What are they building chimney's in your area out of? LEGO!:eek:
Chimney cappings have always been beded on to chimney with a a cement mortar mix.

I thought there must be a DPC or something similar between blocks for dampness prevention and such??
I'm no brickie, so may be wrong.

matty2003

Currently, we receive 85% Signal Strength and 50% Quality. I would greatly assume that this would improve were the dish on the chimney.


I'm at a loss to understand why you think the signal will improve by moving the dish upwards.

Valentia

I have had an aerial on my chimney for 25 years. The aerial is heavier and more likely to damage the chimney than a mini dish IMHO. My Sky dish has been on the chimney for yonks and I never felt that it was increasing the risk of damage. I believe dishes should be on chimneys where possible. It would get rid of a lot of eyesores around the country. They are nearly invisible on the chimney.

watty

Aerial is heavier, but dish has greater leverage / wind load. Unless it is a very large aerial, not for normal TV.

The height of dish makes no difference, I have demonstrated the Sky minidish on 80% quality propped on toolbox in driveway in Co. Clare or Possibley Limerick.

50% is misaligned LNB, or dish or bad cable.

If a tree is a problem you get NOTHING in wet late spring. If the dish can be in sunshine around 11.30 at least autumn & spring, then it will get full signal. The satellite is 22,500 Miles / 45,000 km away approx, 30ft/10m won't help unless its actually blocked. If it is only slightly blocked, then 2ft raise will give perfect signal.

Tony

Valentia wrote:

I have had an aerial on my chimney for 25 years. The aerial is heavier and more likely to damage the chimney than a mini dish IMHO. My Sky dish has been on the chimney for yonks and I never felt that it was increasing the risk of damage. I believe dishes should be on chimneys where possible. It would get rid of a lot of eyesores around the country. They are nearly invisible on the chimney.

Surely your aerial pole is held to the chimney using a lashing kit? This is an entirely different proposition to drilling coach screws straight into the masonry. Eyesores exist only where the dish is on the front of the house in breach of planning regulations.

Berberis

cast_iron wrote:

I thought there must be a DPC or something similar between blocks for dampness prevention and such??
I'm no brickie, so may be wrong.

In fairness to you cast iron you are nearly right.
true there is a damp proof membrane underneath the capping, but if it is put in right, ie a skim of mortar both below and above the membrane then it is structurally sound, the biggest risk may actually be where the membrane is inserted where the stack comes tru the roof and again if that is put in wrong there is a likelyhood of the whole stack moving.

Milktrolley

Ronan|Raven wrote:

What the christ sort of bolts are they using?

The holes that are in the wall are the same ones that have been there for six and a half years. When the new dish was put on in September, the holes in the bracket didn't match the wall perfectly, but it was so close to perfect (i.e tenths of a millimetre in the difference) that it didn't seem like a problem. However, and I only found this out recently, they are the same bolts that have been there for six and a half years. I put this point to him last week, and he said that he didn't have any that could fit at the time, so used the old ones. I've replaced the loose bolts with new ones, and this doesn't solve the problem.

matty2003 wrote:

I'm at a loss to understand why you think the signal will improve by moving the dish upwards.

watty wrote:

If it is only slightly blocked, then 2ft raise will give perfect signal.

It's slightly blocked - by the gutter on the roof. That will tell you how tight the angle is, and why putting it on the right hand side of the house would be far preferable. But, as I've mentioned, our house is semi-detached, so that isn't an option.

byte

Well if the dish is that tight (nearly at right angles with the wall), then a stand off bracket at the back is definitely the best place to put the dish. It won't have to clear the apex of the roof, so pole can be as short as possible.

kbell

Milktrolley wrote:

He has offered to move it up to the chimney - I figure that if he's willing to do that, he'll have no problem moving it to the back of the house

Probably not, but it would be wise to arrange this prior to him calling, to make sure he will have the necessary bracketery and the time to do it.

byte

kbell wrote:

Probably not, but it would be wise to arrange this prior to him calling, to make sure he will have the necessary bracketery and the time to do it.

Yup, good advice.

Zeppi

mine is too at the back hanging on a pole with a diseq motor and I don't have any problems.

rgds
zeppi

Valentia

Tony wrote:

Surely your aerial pole is held to the chimney using a lashing kit? This is an entirely different proposition to drilling coach screws straight into the masonry. Eyesores exist only where the dish is on the front of the house in breach of planning regulations.

Yes Tony the aerial has a lashing kit. Planning regulations?? It's a pity they are not enforced. The country is destroyed with dishes both mini and maxi.

Tony

Valentia wrote:

Yes Tony the aerial has a lashing kit. Planning regulations?? It's a pity they are not enforced.

Thats true I agree in a lot of areas. Another problem is apartment blocks not wired for freedom of choice provider wise forcing people to erect dishes to get what they want.

Milktrolley

byte wrote:

...a stand off bracket at the back is definitely the best place to put the dish. It won't have to clear the apex of the roof, so pole can be as short as possible.

Seems like the most attractive option anyway.

kbell wrote:

Probably not, but it would be wise to arrange this prior to him calling, to make sure he will have the necessary bracketery and the time to do it.

Surely will, hopefully it can be arranged.

cast_iron

Valentia wrote:

Yes Tony the aerial has a lashing kit. Planning regulations?? It's a pity they are not enforced. The country is destroyed with dishes both mini and maxi.

I agree. But if anyone complains about an illegal dish, the council must act.

watty

Many Sky minidishs on fronts of houses are less obtrusive than mega Band I or Band III TV aerials or the MMDS Dish.