Sealing where a velux meets the plasterboard to stop draughts?

gsxr1 · 19-04-2011 7:52am

. from knowing how veluxs are fitted. And put together . They are drafty.
The one shown in the vid is not common. Slate flashing kits.

the brackets that come with a velux is set it up on the battons .( Tiles versions) Which are rough 50mm battons. There is space between the opening and the window frame. There has to be. It does not say anything about using fiberglass to seal this gap on the instructions (unless it has changed in the last year). On tiles there is a very sloppy foam seal to prevent drafts . It does not work very well and falls off sometimes .

I recently did my own attic and sealed around the opening with fiberglass and then brought the vapour barrier all the way into the op and duct taped it to the velux frame before plasterboard. No visible holes. And even after all that, there is still a small draft. Somewhere .. They are known as big outlets for heat and very tricky to seal from wind hitting the roof and blowing hard under the tiles and felt. I have fitted a good few of them over the years

The only reason I can think of for movement is that the brackets where nailed down instead of screwed with the suppled aluminum screws . Which in turn has come lose.
The plasterboard and the plastering are not perfect. That is clear. I have worked (for a short time) with builders who just dont care about detail. Get the house up and finished . Thats all they care about. Unfortunately the bad plastering you see here is everywhere. Boom houses. Thats just the way it is. Go into big estates of the boom years. Like Balbrigan. Lovely looking houses when new. 5 years later they have dryed out and cracked like eggs everywhere. Builders gone bust . No one to claim from.

brendankelly · 19-04-2011 9:36pm

Sorry Snyper, I stand corrected, very well spotted.

In my defence we have one guy that managed to con his way to become a foreman over a metal stud/plasterboard/plastering buisness that does not know how plastering should be done and another that has been fitting them and leaving drafts in them for years and jokes about it.

There are velux windows in the zero energy house and there is ZERO drafts. I did not fit the velux but it was fitted properly and if it can be done on one house it could be done on every house.

mfceiling · 19-04-2011 9:41pm

brendankelly wrote: »

You said it all when you stated that you are aligned with people that do not know how to plaster. You also stated that you knew skimmers that work for 5 e a meter.
Ryanair tradesmen and a few mushroom contractors are all that would work for that.

Correction they do know how to plaster - you maintain skim coat is put on then put on again - i've never, ever seen this done.
Even when we had site visits from gypsum (every week on a certain job) did they ever stop the plasterers and ask why they didn't put on gypsum skim in 2 coats.
The gypsum rep told us that plasterboard is 12.5mm because the skim coat should be no more than 2.5mm which when boarded and skimmed both sides of a 70mm metal stud partition equals 100mm.
As for the 5 euro a square metre - that is a labour only price and is the going rate for dublin.
You maintain €12 a metre - i have a friend who served his time with a company where the owner is a member of the CIF, the building limes forum scotland, the georgian society and listed with the dublin civic trust - he told me that if you want to pay €12 a metre he will leave dublin and go to wherever you want him to!!

AckwelFoley · 19-04-2011 10:03pm

MF, the "second" coat is and isnt a second coat. The second coat is applied alot lighter than the first coat, - i prefer to use a pvc float on for the second coat, essentially you are using it to even out the first coat, its done as the first layer begins to dry - now ive seen plasterers use the steel trowel on the second coat, but i fnd its not as good at evening out the skim as it doesnt pull out the humps and fill the hollows as well because the steel trowel is smooth - its my fathers way and now my way and hes old school.

Im sure that there are skimmers that night not apply a second coat, i wouldnt judge them until ive seen their work, but in essance, one two or 12 coats is not the problem the op has its the fact the crack has appeared at the window, and the only fault i can really make (other than the way the slab is fitted) is that the skimmer didnt pull the trowel from the windows edge enough hence its a bit rough looking (granted ive seen worse)

Brendan,im not overly familiar with airtightness, but as far as i know - and i stand to be corrected, the air tightness membrane is enveloping the habitable areas of the house - the house fabric ie the roof, still needs to breath, so as far as i know the attic space if not a habitable one is outide of the membrane, in which case the velux flashings will be too.

The more i think about it the more i suspect if there is a draft, it might be comming from the vent in the window

saltandpepper10 · 19-04-2011 10:48pm

mfceiling wrote: »

Correction they do know how to plaster - you maintain skim coat is put on then put on again - i've never, ever seen this done.
Even when we had site visits from gypsum (every week on a certain job) did they ever stop the plasterers and ask why they didn't put on gypsum skim in 2 coats.
The gypsum rep told us that plasterboard is 12.5mm because the skim coat should be no more than 2.5mm which when boarded and skimmed both sides of a 70mm metal stud partition equals 100mm.
As for the 5 euro a square metre - that is a labour only price and is the going rate for dublin.
You maintain €12 a metre - i have a friend who served his time with a company where the owner is a member of the CIF, the building limes forum scotland, the georgian society and listed with the dublin civic trust - he told me that if you want to pay €12 a metre he will leave dublin and go to wherever you want him to!!

honestly mf its always a two coat process anything else is a diy bodge at best which really shows up when painted.all your expieriance is in taping and jointing i would imagine ,which can also be a high quality finish when done right,but brendan is completely rite on this one

brendankelly · 19-04-2011 11:03pm

mfceiling wrote: »

Correction they do know how to plaster - you maintain skim coat is put on then put on again - i've never, ever seen this done.
Even when we had site visits from gypsum (every week on a certain job) did they ever stop the plasterers and ask why they didn't put on gypsum skim in 2 coats.
The gypsum rep told us that plasterboard is 12.5mm because the skim coat should be no more than 2.5mm which when boarded and skimmed both sides of a 70mm metal stud partition equals 100mm.
As for the 5 euro a square metre - that is a labour only price and is the going rate for dublin.
You maintain €12 a metre - i have a friend who served his time with a company where the owner is a member of the CIF, the building limes forum scotland, the georgian society and listed with the dublin civic trust - he told me that if you want to pay €12 a metre he will leave dublin and go to wherever you want him to!!

Mother of God but what next???. You are now telling us that a stud partition should only be 100 mm thick.

The metal stud replaced the 4 by 2 which is 100mm. The 4 by 2 , boarded is 125 mm and the doorframe is 5 and a quarter or 133 mm. Therefore 8 mm skimming. That is 2 coats.

I do not know how you got away with single boarding stud partitions. Any time I saw them done they were double boarded and skimmed and the doorframe fitted perfectly. i.e. 70 mm stud, 50 mm boards and 6 to 8 mm skim = 5 1/4 inches the size of the doorframe. You must have made a fortune during the boom.

As for your friend. He served his time as a lime plasterer and now you are trying to pawn him off as a gypsum plasterer. ?/. No thanks. He does not even know what he is.

brendankelly · 20-04-2011 12:58am

snyper wrote: »

MF, the "second" coat is and isnt a second coat. The second coat is applied alot lighter than the first coat, - i prefer to use a pvc float on for the second coat, essentially you are using it to even out the first coat, its done as the first layer begins to dry - now ive seen plasterers use the steel trowel on the second coat, but i fnd its not as good at evening out the skim as it doesnt pull out the humps and fill the hollows as well because the steel trowel is smooth - its my fathers way and now my way and hes old school.

Im sure that there are skimmers that night not apply a second coat, i wouldnt judge them until ive seen their work, but in essance, one two or 12 coats is not the problem the op has its the fact the crack has appeared at the window, and the only fault i can really make (other than the way the slab is fitted) is that the skimmer didnt pull the trowel from the windows edge enough hence its a bit rough looking (granted ive seen worse)

Brendan,im not overly familiar with airtightness, but as far as i know - and i stand to be corrected, the air tightness membrane is enveloping the habitable areas of the house - the house fabric ie the roof, still needs to breath, so as far as i know the attic space if not a habitable one is outide of the membrane, in which case the velux flashings will be too.

The more i think about it the more i suspect if there is a draft, it might be comming from the vent in the window

I know vety little about it either. But BUT . We both know enough to know we know little about it.

gsxr1 · 20-04-2011 7:38am

snyper wrote: »

LOADMASTER
Brendan,im not overly familiar with airtightness,

dont worry. From reading his mental posts over the last year . I dont think he does either .

mfceiling · 20-04-2011 12:05pm

Sorry Brendan but I never conned my way into being a foreman. I simply got the job from being good at what I do..metal stud partitions, and MF Ceilings.

Metal stud comes in 50mm, 70mm, 90mm and 146mm. Have you ever been on a building site or read a set of drawings? Some jobs specify 1 layer of Plasterboard on each side of the walls, some are double sided, some are fire rated, some are non fire rated, some have soundblock board, some have moisture board, some are shaft wall detail...in other words...what the architect specifies on the drawing is what you obey.
I hope you understand this...no 2 jobs are the same.
By the way I never made a fortune during the boom..
As a side note...if you want references of the quality of my work I will pm you some of the happy boards members I have worked for recently....word of mouth recommendations are hard to beat!

brendankelly · 20-04-2011 10:07pm

mfceiling wrote: »

Correction they do know how to plaster - you maintain skim coat is put on then put on again - i've never, ever seen this done.
Even when we had site visits from gypsum (every week on a certain job) did they ever stop the plasterers and ask why they didn't put on gypsum skim in 2 coats.
The gypsum rep told us that plasterboard is 12.5mm because the skim coat should be no more than 2.5mm which when boarded and skimmed both sides of a 70mm metal stud partition equals 100mm.
As for the 5 euro a square metre - that is a labour only price and is the going rate for dublin.
You maintain €12 a metre - i have a friend who served his time with a company where the owner is a member of the CIF, the building limes forum scotland, the georgian society and listed with the dublin civic trust - he told me that if you want to pay €12 a metre he will leave dublin and go to wherever you want him to!!

I would safely bet I was on building sites before you were born and judging from your post will be on sites after you.

I do not want any references but I would like the details of the person that signed off on a single boarded 70 mm metal stud partition and the details of architects that specify single leaf boarding for partition walls.

mfceiling · 20-04-2011 10:26pm

brendankelly wrote: »

I would safely bet I was on building sites before you were born and judging from your post will be on sites after you.

I do not want any references but I would like the details of the person that signed off on a single boarded 70 mm metal stud partition and the details of architects that specify single leaf boarding for partition walls.

Intel - 146mm stud with 2 layers of 15mm fireline board per side
Superquinn Rathgar - 70mm stud with single layer of 12.5mm board
Creche Aungier Street - 50mm stud with 2 layers of soundblock board per side
BNP Bank - 70mm stud with single layer of GTEC Aqua Board
Cuisine de France - 70mm stud with double layer of 12.5mm board
School Balbriggan - 70mm stud with one layer 12.5mm board and one layer of 12.5mm duraline board per side
Apartments Hanover Quay - 70mm stud with one layer of 12.5mm board per side
Ladybird Blanchardstown - 146mm stud with single layer of 12.5mm board per side

Just off the top of my head brendan.
Ring a few architects to see if they specify single layer of 12.5mm board on to a 70mm metal stud partition.

http://www.british-gypsum.com/pdf/WB09_Partition_and_walls_systems_09.pdf

Give that link a quick read.........it's the gypsum white book detail for single layer of plasterboard on to 70mm stud walls......has all the details you'll need from fire ratings to sound insulation.

Why would you like the details of an architect who signs of on a single boarded wall?
Do you not think a fully qualified architect would not know the difference in specs on different wall designs - board types, metal thickness etc?
Most of the architects i worked under knew the gypsum white book inside out - often climbing up though scaffolds to check deflection head details on partition walls we built - which by the way (for a "so called" conman) we never had a single wall condemned on any project we ever worked on.

mfceiling · 20-04-2011 10:30pm

snyper wrote: »

MF, the "second" coat is and isnt a second coat. The second coat is applied alot lighter than the first coat, - i prefer to use a pvc float on for the second coat, essentially you are using it to even out the first coat, its done as the first layer begins to dry - now ive seen plasterers use the steel trowel on the second coat, but i fnd its not as good at evening out the skim as it doesnt pull out the humps and fill the hollows as well because the steel trowel is smooth - its my fathers way and now my way and hes old school.

Im sure that there are skimmers that night not apply a second coat, i wouldnt judge them until ive seen their work, but in essance, one two or 12 coats is not the problem the op has its the fact the crack has appeared at the window, and the only fault i can really make (other than the way the slab is fitted) is that the skimmer didnt pull the trowel from the windows edge enough hence its a bit rough looking (granted ive seen worse)

Brendan,im not overly familiar with airtightness, but as far as i know - and i stand to be corrected, the air tightness membrane is enveloping the habitable areas of the house - the house fabric ie the roof, still needs to breath, so as far as i know the attic space if not a habitable one is outide of the membrane, in which case the velux flashings will be too.

The more i think about it the more i suspect if there is a draft, it might be comming from the vent in the window

That's what i've seen all plasterers do snyper - i wasn't aware that a second coat was being applied at that stage but it makes sense with the way you have described it.
Good to see somebody with a brain posting here

brendankelly · 20-04-2011 11:56pm

mfceiling wrote: »

Intel - 146mm stud with 2 layers of 15mm fireline board per side
Superquinn Rathgar - 70mm stud with single layer of 12.5mm board
Creche Aungier Street - 50mm stud with 2 layers of soundblock board per side
BNP Bank - 70mm stud with single layer of GTEC Aqua Board
Cuisine de France - 70mm stud with double layer of 12.5mm board
School Balbriggan - 70mm stud with one layer 12.5mm board and one layer of 12.5mm duraline board per side
Apartments Hanover Quay - 70mm stud with one layer of 12.5mm board per side
Ladybird Blanchardstown - 146mm stud with single layer of 12.5mm board per side

Just off the top of my head brendan.
Ring a few architects to see if they specify single layer of 12.5mm board on to a 70mm metal stud partition.

http://www.british-gypsum.com/pdf/WB09_Partition_and_walls_systems_09.pdf

Give that link a quick read.........it's the gypsum white book detail for single layer of plasterboard on to 70mm stud walls......has all the details you'll need from fire ratings to sound insulation.

Why would you like the details of an architect who signs of on a single boarded wall?
Do you not think a fully qualified architect would not know the difference in specs on different wall designs - board types, metal thickness etc?
Most of the architects i worked under knew the gypsum white book inside out - often climbing up though scaffolds to check deflection head details on partition walls we built - which by the way (for a "so called" conman) we never had a single wall condemned on any project we ever worked on.

You are proving my point for me.

Intel Double board
super quin Single board (Just a supermarket)
Crèche Double Board
Bank Single board (toilets)
Cuisine de France Double board
School Double board
Apartment Single board (Maybe you should check this one again)
Ladybird 146 stud and single board.

brendankelly · 20-04-2011 11:56pm

mfceiling wrote: »

That's what i've seen all plasterers do snyper - i wasn't aware that a second coat was being applied at that stage but it makes sense with the way you have described it.
Good to see somebody with a brain posting here

What a u turn. Now all are putting on two coats. But you did not know what they were at.

You should just admit you were wrong.

Ordinary man · 21-04-2011 6:57pm

brendankelly wrote: »

What a u turn. Now all are putting on two coats. But you did not know what they were at.

You should just admit you were wrong.

70mm stud with single slab each side is the most common type of partition being used these days and would be considered standard. While it's obvious you have great knowledge of plastering, you let yourself down when it comes to partitions and ceiling systems:(

AckwelFoley · 21-04-2011 10:11pm

Ordinary man wrote: »

70mm stud with single slab each side is the most common type of partition being used these days and would be considered standard. While it's obvious you have great knowledge of plastering, you let yourself down when it comes to partitions and ceiling systems:(

What is used for door frame with 70mm stud and 2 x 12.5mm slabs?

Ive never actually used metal stud, i always use 4" timber stud and use the ordinary internal doorframe, but with a 70mm what doorframe is used?

delly · 21-04-2011 10:31pm

Well holy mother of God, the innocent OP starts a thread regarding gaps in his plasterboard and the world implodes. For the record it doesn't seem a big job to me, a bit of white silicone would keep me happy, but we are all allowed our opinions as to how to sort an issue. One thing the OP will not do I assume is refit the whole window, now that would be a bit much imho.

And opinions is what it comes down to really, from the simple to the complex, to the measured. What I don't like however is piss taking and provoking of peoples opinions. While a lot of ideas differ, its how you present them that matters and brendankelly I'm looking in your direction. Having looked over the thread, you are rude, insulting and can't seem to stop poking people in the eye. I'm not one who knows you but having looked over your history I can see what you have been up to in other forums. Consider this your one and only warning. There won't be any infractions, just a short ban for your next misdemeanor, then a perm ban for the one after that. This is a relaxed forum and the last thing I need if an upstart like yourself.

Ordinary man · 21-04-2011 10:41pm

snyper wrote: »

What is used for door frame with 70mm stud and 2 x 12.5mm slabs?

Ive never actually used metal stud, i always use 4" timber stud and use the ordinary internal doorframe, but with a 70mm what doorframe is used?

The frames are 103 mm usually. I don't personally fit the frames, just leave the openings but no complaints yet;)

As mfceilings says the partitions are as called up, be it 70mm or 90mm stud, single or double slab, moisture, fire, sound or plain slabs.

AckwelFoley · 21-04-2011 10:56pm

Ordinary man wrote: »

The frames are 103 mm usually. I don't personally fit the frames, just leave the openings but no complaints yet;)

As mfceilings says the partitions are as called up, be it 70mm or 90mm stud, single or double slab, moisture, fire, sound or plain slabs.

Ah, a 103 by 44 i assume.. Its a very light frame for a door.. esp when you have wild kids and an angry woman slamming doors!

brendankelly · 22-04-2011 12:35am

With respect Delly the thread started with the OP asking for advice. He clearly had a bad plastering job done which I said (the truth) and it then developed into whether plastering should be done in one or 2 coats. I pointed out (again the truth) that it should be done in 2 and others said it should be done in one coat. Snyper, saltandpepper, Ordinaryman and someone else agreed with me while MF ceilings said his plasterers from Cork to Donegal were doing it in one coat and they were right. There was a debate and I admit I wrongly snapped at snyper for which I apologised for and to snypers credit he did not run to you telling tales.
I have 5 daughters and I gave the OP the exact advice I would give them and I would have hoped that if they had asked for advice they would get honest and direct advice and that was to rip it out and get the job done properly. My daughters or in this case the OP would have the option as to whether take my advice or not.

DonalK1981 · 28-04-2011 10:21pm

I thought this discussion would go on forever! Glad the questions were put to rest. 2 coats, not one! Hope the OP got their window sealed, please let us all know of the outcome. I am sorry the banter has ended, it was one of the most entertaining threads I've read in a while...

leet44 · 09-05-2011 10:28pm

Err...........my roof window has a fecking big crack beside the plasterboard abutment & I'm sure it's where there was a mouse stomping about on me roof the other night....................mind you it was a hippopotomouse:D

phil mccrackin · 09-05-2011 10:33pm

did it get two coats of plaster leet?

leet44 · 09-05-2011 10:34pm

just some lime mucker..........d'ya think the mice like lime?

thekooman · 31-05-2011 9:05pm

great post folks.... sorry, haven't been on for awhile. I got around the window filled in with painters caulk and by using masking tape as a guide so as to keep it off the timber in the same way that painters would do skirting and architrave. it looks much better now and has stopped some of the draughts.

Sealing where a velux meets the plasterboard to stop draughts?

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