Velux window installation Questions

[martyc]

Hi,
Am at the point in slating my roof where i need to pop in my velux frames.
I have a few questions!

(slate roof small velux 55*98 GGL plus flashing kit EDL)
Have all the instructions but still one or 2 things not explained very well

1.Should the window frame(bottom) sit immediately above the top of a row of slates?...some pics show this while others dont in the instructions.

2.It shows in the instructions the installation of felt arouond the window...this didnt come in the flashing kit...do i just cut some up??

3.Also it shows in the instructions a metal piece above the window...like slate trim you would use on the side of a roof...i imagine this is to stop the wind getting under the slates...what is this piece of kit and do i need it ?

4.The flashing @ the bottom...from the pics it looks like it goes under the slates...surely it should go on top of the slates...and vice versa for the top flashing

Sorry for all the questions just want to have it straight in my head before i go at it tomorrow.

Cheers,
MArty.

 

[noseall]

[quote="martyc"

1.Should the window frame(bottom) sit immediately above the top of a row of slates?...some pics show this while others dont in the instructions.

you will need to fix a tile batten 80mm up from the top edge of the bottom row of tiles. the bottom window brackets are fixed to this batten. the top fixings are fixed into another batten that you will fix according to the size of the window.

2.It shows in the instructions the installation of felt around the window...this didn't come in the flashing kit...do i just cut some up??

haven't a clue what you're on about here. maybe your looking at the alternative, lead flashing instructions.

3.Also it shows in the instructions a metal piece above the window...like slate trim you would use on the side of a roof...i imagine this is to stop the wind getting under the slates...what is this piece of kit and do i need it ?

there is an adjustable tile lift, with two bands or straps, that the top row of tiles will need to sit on in order to give them their 'kick'. yes, this item is important.

4.The flashing @ the bottom...from the pics it looks like it goes under the slates...surely it should go on top of the slates...and vice versa for the top flashing

the bottom row of tiles will need to be in place right from the outset and yes, the lower flashing sits on top of these tiles. all the rest of the flashings sit below the tiles.

Cheers,
MArty.[/quote]

 

[martyc]

Cheers nosell,
However ive trawled the web and ive pretty much got my head around it now(i think!!)

The 80mm you are on about for the bottom batten is only true for tiles if i am correct(seepage 5 of this link http://www.above-it-all.co.uk/media/GGL_GGU_Installation.pdf versus page 6 of the same link for slate)
...for slates it is different and i think the frame fits onto a standard lat unless you are using a very non standard guage.

The felt thing im on about is a Velux product they call an underfelt collar "BFX" is the code but i went to 2 builders merchants this morning and neither stock them as apparently no one uses them http://www.above-it-all.co.uk/media/BFX_Underfelt_collar.pdf ....there are instructions to cut some membrane up and use use that,ill give that a go!!

Cheers for the other tips...will have to get some of them tile lifters.

Cheers,
Marty.

 

[jono_h]

Item 2. This is like a big nappy! Basically it ensures a waterproof seal in the felt. I did this in my first extension, but the builders in my current extension just cut a hole and threw them in!
If you want to follow the instructions then just use some felt and silicone.

 

[martyc]

Cheers for that...i found that out somewhere already!!
Anyways i put them in last saturday...would have gotten them in a lot quicker if i hadnt read the ever so confusing instructions!!

Anyway for anyone else heres what i found.
The nappy thing..if u can get it do...i couldnt so i just cut the felt so that it runs all the way up the sides of the velux and stapled it in...i also cut up some extra felt to create an apron around the window to deflect any stray water etc...in reality its probably overkill(also i have a huge overlap on my felt which happens to cover the entire velux top to bottom so that helps a lot too!!...it was either have a huge overlap (900mm) or else cut it and chuck it in the bin si i used it on the roof!!)

For slates the bottom of the velux (in my case...see window size in OP) is supported by a regular slate batten and the top needs an extra batten wherever the top ends up so to speak.

My other questions were answered by noseall.

Cheers,

Marty.