Warm Deck Dormer Roof - Is this correct?

andyuk2005

Sorry Cyclone but when people disagree with well known industry information and come up with their own theory about different roof types, I can't help but feel obliged to correct them! And the conversation of different roof types completely detracted from my original query.

As mentioned, as people will be reading this and searching it, for their benefit I'm sure it will be useful to provide any information regarding your idea that cold is better than warm decks. Otherwise best to retract it! We don't want to confuse anyone. But as mentioned all information regarding the differences have pointed to warm decks being considerably better than cold, and every youtube video or internet source will generally back that up. As I said, give that guy a call and see what he says!

andyuk2005

And thinking about it, did you actually watch the video??! The guy does both types of roofs, and since he actually states warm decks are cheaper to do generally, why would he be pushing warm decks?! Surely if he was out to con people of their money he would say cold decks are better as he would get more money!!

cyclonebri1

Did you say proof earlier????

Print the proof in that case.

You asked for advice.

Most on here would fall shy of offering advice, for legal reasons.
You also said you were considering legal proceedings against the company that did your roof, bad move if that really was the case, again for legal reasons.

You do seem not to want to accept any alternative opinions, (somewhat different from advice), but you can do that, just don't rubbish anything that you don't want to consider.

Where you actually asking for help or spamming?? you have me thinking now.

System

as someone that has detailed manys a roof (both warm/cold) I can confirm 100% that either can be cheaper/easier to build dependant on the specific build up used.
If you want proof that warm is not always the best way, why not ask a volume house builder why they prefer cold roofs over warm roof (or at least, any of the national companies I have produced drawings for always prefer a cold roof)
Otherwise I could send you a few of the different specifications and you can price them up if you wish...

Also the logic behind the heating costs points raised is fairly straight forward - more volume to heat with the same useable space = more heat input required, that is an inescapable fact

a lot of the propaganda in the video is the ease of using this construction in retrofit applications - why would a contractor be pushing the easiest way to retrofit a flat roof?!
The examples used in the thermal image camera are clearly from badly build roofs, it would be better to compare well built examples - you can build a warm roof just as badly (as you have a prime example of op!) Thermal bridging over each type of roof can be detailed out, but the critical details are the junctions

teneighty

If you want proof that warm is not always the best way, why not ask a volume house builder why they prefer cold roofs over warm roof (or at least, any of the national companies I have produced drawings for always prefer a cold roof)

When was the last time you designed a cold deck flat roof for a national house builder? I have not specified or even seen a new one apart from small DIY jobs for at least 10 years, probably more like 15. I would never recommend a client has one unless circumstances made a warm deck flat roof impossible. Pitched roofs are a different matter.

A warm deck flat roof is cheaper, quicker to build and if done properly eliminates any interstitial condensation. Trying to cross vent a cold deck flat roof has always been a nightmare. IMHO.

System

teneighty wrote: »

When was the last time you designed a cold deck flat roof for a national house builder? I have not specified or even seen a new one apart from small DIY jobs for at least 10 years, probably more like 15. I would never recommend a client has one unless circumstances made a warm deck flat roof impossible. Pitched roofs are a different matter.

A warm deck flat roof is cheaper, quicker to build and if done properly eliminates any interstitial condensation. Trying to cross vent a cold deck flat roof has always been a nightmare. IMHO.

sorry, I was referring to warm/cold roofs in general rather than flat roofs specifically - volume house builders (or at least the ones I have worked with) try to avoid flat roofs anywhere! the only time I have done something similar (i.e. low mono pitch) was indeed a cold roof build up (was originally intended as warm but in house team decided it was too expensive)

and both types are fine if "done properly" but the costs/ease of build can vary depending on the specs/finishes

andyuk2005

Yes I was referring to flat roofs as per the picture attached.

Cyclone, what's your beef??! I really don't understand some of your replies and why they are put in such a manner! I can't help but think you must like to pick holes in people's opinions, arguments and queries!

My 'proof' that (flat) warm decks are GENERALLY better than cold decks is evident across almost all literature, videos and guidance! I've had numerous roofers tell me this, along with builders, surveyors, building control and anyone else who has an opinion on this! As I said, for the sake of people who might come across this, if you are so adamant about your position then please back it up! Otherwise you'll look silly!

And to repeat myself, my question was regards to a specific issue with a warm deck, and had nothing to do with the difference between hot and cold!! So your 'advice' is irrelevant and unwarranted!! Thanks anyway though!

I would like to say thank you to everyone who has made a positive contribution to this thread however! I do really appreciate it!

And suuuure, you think I may be a spammer. This is hilariously ridiculous! Seems like playground behaviour to me, in which case, I bet my dad can beat up your dad!!

System

andyuk2005 wrote: »

if you are so adamant about your position then please back it up! Otherwise you'll look silly!

you posted "evidence" which was effectively a sales video for a company that supplies warm decks for retrofit applications - all I am saying is that there are two different ways to do it and one is not necessary cheaper/easier/better than the other in every application, a lot depends on the specification and application of the particular bit of roof.
For retrofit applications warm roof certainly has advantages - mainly that it has less disruptive work required inside, however the advantages can be totally undone when badly built, as this thread is evidence
A newly constructed (flat) cold roof with the correct insulation and ventilation can perform very well in the right situation - older cold roofs have a reputation for being problematic, mostly through poor construction/insufficient ventilation which is probably why you have heard builders/surveyors saying that - however current techniques/products are much better for this application

cyclonebri1

the_r_sole wrote: »

as someone that has detailed manys a roof (both warm/cold) I can confirm 100% that either can be cheaper/easier to build dependant on the specific build up used.
If you want proof that warm is not always the best way, why not ask a volume house builder why they prefer cold roofs over warm roof (or at least, any of the national companies I have produced drawings for always prefer a cold roof)
Otherwise I could send you a few of the different specifications and you can price them up if you wish...

Also the logic behind the heating costs points raised is fairly straight forward - more volume to heat with the same useable space = more heat input required, that is an inescapable fact

a lot of the propaganda in the video is the ease of using this construction in retrofit applications - why would a contractor be pushing the easiest way to retrofit a flat roof?!
The examples used in the thermal image camera are clearly from badly build roofs, it would be better to compare well built examples - you can build a warm roof just as badly (as you have a prime example of op!) Thermal bridging over each type of roof can be detailed out, but the critical details are the junctions

:T:T:T Well I don't install roofs, bur I do have an engineering degree, and it's really is as simple as the highlighted bit:T:T:T

cyclonebri1

andyuk2005 wrote: »

Yes I was referring to flat roofs as per the picture attached.

Cyclone, what's your beef??! I really don't understand some of your replies and why they are put in such a manner! I can't help but think you must like to pick holes in people's opinions, arguments and queries!

My 'proof' that (flat) warm decks are GENERALLY better than cold decks is evident across almost all literature, videos and guidance! I've had numerous roofers tell me this, along with builders, surveyors, building control and anyone else who has an opinion on this! As I said, for the sake of people who might come across this, if you are so adamant about your position then please back it up! Otherwise you'll look silly!

And to repeat myself, my question was regards to a specific issue with a warm deck, and had nothing to do with the difference between hot and cold!! So your 'advice' is irrelevant and unwarranted!! Thanks anyway though!

I would like to say thank you to everyone who has made a positive contribution to this thread however! I do really appreciate it!

And suuuure, you think I may be a spammer. This is hilariously ridiculous! Seems like playground behaviour to me, in which case, I bet my dad can beat up your dad!!

And lets guess?, you have a bigger diick than me???????

I'm out, ask for help or give it, don't try both.