Fitting cills to Rationel windows

[jamieled]

Our Rationel windows were supplied with some aluminium cills. The windows themselves have a small groove routed into the bottom of thr frame, we assume to take the cills.

For anyone else who has these, how did you fix them to the window frames? The cills have a couple of holes in them, but once they're pushed into the frame the holes disapear and become useless. If it's relevant, the cills project out over vertical board on board timber cladding.

 

The pic below shows the cills sitting under the frame, on top of the cladding.

[ProDave]

Can you post an end profile shot of the Cill?

 

They look different to the Cills we got.  I think the issue is Rationel don't supply the cill and ADW (I assume that's where they came from) get the cills made locally.

 

We had a slight issue with ours, the main batch, the cills were a damned tight fit into the groove, but okay.  Then I had one more window delivered on it's own and the cill provided was an almost impossibly tight fit.  It went in, but if I had a router I might have widened the groove a bit.

 

What is that groove in the front face showing? That looks like the internal groove for a window board?

 

Not sure how uch you will see if you zoom in on this, it's the only picture I have of the window cills before the cladding and render was finished.

[jamieled]

@ProDave, thanks. Profile photo below.

 

The left hand side is the side that fits into the groove on the frame.

 

Not sure the groove on the front face is anything more than cosmetic (assuming we're looking at the same thing).

 

Main issue is that I can get the cills into the groove, but they won't stay there and so some support is needed. Considering thick glue/sealant dabs at the moment. The fixing holes are a red herring I think.

 

Frustratingly, one of the windows has no groove at all. I've only just found this out, and so I'll need to bodge something as I don't really want to take the window out.

[ProDave]

So you have the opposite problem to me.  Our cills were extruded aluminium and the bit that went in the window was ribbed, making it incredably tight.  you have a folded cill.  Just fit it with a good waterproof adhesive / sealant like stixall, sikaflex, CT1 etc.

 

You appear to have a broad horizontal groove in the front face that serves no purpose. do all your windows have that?  One thing I liked about Rationel was their simple crisp clean  profile. We don't have that. 

[jamieled]

The broad groove is just where the opening windows fit into the window frame. There is one less groove on the fixed frame windows.

 

Or are you referring to something else?

[ProDave]

10 minutes ago, jamieled said:

The broad groove is just where the opening windows fit into the window frame. There is one less groove on the fixed frame windows.

 

Or are you referring to something else?

Yours are painted timber?  Ours are aluminium clad and that detail is different, that's all that was confusing me.

[jamieled]

Nope, we're also alu clad, so I'm still confusing you!

 

In my first photo, I see two grooves. One very narrow one, which I assume is for fitting/replacing the glazing. The second, wider groove is where the window shuts into the window frame when it opens and closes. To me it looks similar to what I can see on your photo when I zoom in.

 

 

[Roundtuit]

Hi.  I've still got this job to do, and I don't think they're supposed to fit in the grooves.  All of our windows have a ~20mm  batten fixed to the bottom of the frame, set back about 20mm from the Ali face of the frame to screw the cill pressings to.

Edited January 18, 2020 by Roundtuit

[Roundtuit]

If it helps, ours look like this:

 

[jamieled]

Thanks! The windows look the same. Did you fit the 20mm baton yourselves or did they come with them attached from Rationel? In any case it sounds like a way I can deal with the window that has no groove.

Edited January 18, 2020 by jamieled
Didn't read the whole reply!

[Roundtuit]

No problem!  We fitted the battens when we put the windows in.  I've just dug out the installation drawings that show the general principle; hopefully you can get some timber in there to fix to one way or another.

Edited January 18, 2020 by Roundtuit

[Stones]

We had custom cills folded and painted as we needed to bridge 140mm of EWI.  Managed to get them (folded and painted to match our windows) for around half the price of the Rationale ones.   We simply offered the cill up into the groove on the underside of the window frame, then closely fitted the EWI underneath to support the cill, foaming what gap remained.  Rock solid. 

[Andrew]

These details might help too - https://www.rationel.co.uk/media/1708641/rationel-auraplus-typical-interface-drawings.pdf

[gcm]

Another Rationel Forma+ Alu clad + secondary cill detail
Aftermarket cill sourcing and application does seem to vary.  
Not sure if this is optimal but it seemed to make sense for our application.
We were dealing with "too flat" existing deep granite exterior cills in a refurb and we ended up like this.  

Windows sized to allow for aftermarket Alu cills. 
Upstand Groove to rear edge of cill only. No additional interlocking profile.
3 lines of arbo full length to cill top face far enough back to avoid visible gloop or compromising the drip/free air draining to front profile. 
Screwed cill up onto bottom of frame. 
Then Compriband trio around the cill and the frame as a unit.
Fit to aperture (brick and a rough flat granite cill in this case).  More arbo to front cill edge to granite.  Insulation and Alu plate to arch as picture.

We now have a sensible "drip" with no timber sat in the water on the granite so hopefully these windows won't rot as quickly as the old ones.

The school solution would probably be a full depth Alu cill to come out to the front edge but it would look bad in this application hence the compromise in the photo.