How to build an external window frame?

If the builder has fixed the window permanently in place, the timber wedge can be removed. I suggest spraying the inside and outside gaps around it with Parfix 340g Expanding Foam Filler. This will fill in the gap and you don't have to use the paper towels anymore. The expanding foam will come out of the gap, and I recommend waiting for the foam to fully cure before you trim it with a Craftright 18mm Snap Off Knife. To further seal off the window I suggest using Sika 310ml Grey Concrete Sikaflex Pro+ Polyurethane Sealant on the outside and inside trim of the window. But if the gap is more than 5mm in width you'll need to use a timber trim to fill in the gap

In regards to the trim, you can use spotted gum, merbau, black butt and ironbark. There is also the 42 x 18mm 5.4m Moulding H3 Treated Pine FJ Primed 4 Edge Pencil Round LOSP. This is treated pine and just needs to be cut down to serve as window trim. I suggest making sure to paint the cut ends to protect it from the weather. Please keep in mind that you'll need to cut this at home as the store saw will not do precision cuts. Once you've cut the timber to the correct size you can then glue and screw the pieces to the outside of the window. I propose using Selleys 320g Liquid Nails Construction Adhesive and Zenith 8 - 10 x 40mm Galvanised Countersunk Rib Head Timber Screws.

I suggest putting on more Sikaflex on the outside and inside of the trim to fully seal it in place.

Let me tag @Dave-1 and @Nailbag for their recommendations.

If you need further assistance, please let us know.

Eric

Good morning @BoeingFan

I was going through your questions and @EricL's answers pretty much cover them.

Some other questions

- I would screw through the trim into the studs and also into the window frame. (My thinking is to make sure its joined) predrill through the cement sheet. (It looks like fibro so be aware of asbestos)

- Is the chock doing anything, as in holding the window in place? If the builder has secured the stained glass frame it really shouldnt be needed?

- Do you want 45degree corners or are after a straight edged corner? Depends on what your other windows look like is how I would approach that.

Dave

Nailbag

The steps @EricL is basically already how I would approach this. First you need to fix the widow to the side timber studs (vertical frame timber) with screws as @Dave-1 mentioned or nails both pilot holed first through the window frame.

Go sparingly with the expanding foam and read the instructions. Most expand 10-15% of what you apply. Once dried, you can cut the excess with something like a bread knife is ideal flush to both the inside and outside of the window frame.

Ideally you would then put internal wall panelling on the left side of the window to match the right. Then install the trim's @EricL mentioned to cover the gap between the window and the wall. This is called architrave.

Nailbag

https://www.workshop.bunnings.com.au/discussion/comment/54106#Comment_54106

Thank you so much @EricL @Nailbag and @Dave-1

There are 4 nails in the inside of the window frame going in to the studs, 2 on each side, 1 at the top, 1 at the bottom. The builder has told me to leave the chock in place, but I'm inclined to punch the nails in flush, then remove the chocks and see if it stays in place 🤞

So today I bought some 64mm x 19mm spotted gum hardwood, some gap filler, a caulking gun, and a handsaw.

I didn't buy the expanding foam because I'm nervous as hell that I don't know how to use it and the place will look like an exploded laundromat with foam everywhere.
I also hadn't seen the @EricL's post before shopping, and bought No More Gaps Exterior (White) instead of the Sika 310ml Grey Concrete Sikaflex Pro+ Polyurethane Sealant. Is there a particular advantage to the Silka over the Selleys? I notice the Silka states, "...is designed for movement and connection joints in concrete and masonry facades." The gap filler will be used between painted timber planks, and painted timber and painted fibro, so will the Selleys be as effective?
In relation to your question @Dave-1 about 45º angle cuts; I think this would be great but I'm a nervous novice. Perhaps I could try some cuts with my sliding drop saw on some old bits of timber out in the back yard. I do like the idea of the 45º corners.
My builder told me to put the new external frame 3mm from the inside of the window frame to give it a 'quirk'. This will be exciting. The yard will look like a sawmill whilst I get this down pat.

The first thing I will do is paint the 'raw' fibro with Dulux one step prep on Saturday, then the rest can begin. I look forward to any followups you may have to what I've written above, and as always I'm very grateful for your help.

Cheers,

Jason

https://www.workshop.bunnings.com.au/discussion/comment/89279#Comment_89279

Let me tag @Dave-1 to make sure that they see your question. Remember that the best way to find out how things work is to test it first. You can always grab a can of expanding foam and do a small test on piece of timber to give you an idea of how it works. Selleys No more gaps exterior will do just fine and provide the same amount of flexibility. My best advice is to add extra screws to the window frame close to where the nails are to prevent movement. Practice first with old timber offcuts to get a feel for the cuts and where the cuts should be placed.

If you have any other questions we can help with, please let us know.

Eric

https://www.workshop.bunnings.com.au/discussion/comment/110425#Comment_110425

Good Evening @BoeingFan

🙂 Nice work on sourcing the bits you want, even better that you have a drop saw as it makes life soooooo much easier and believe me its FUN when you see what you can do, the 45deg angles are just a start!

As @EricL has suggested, test it out on some offcuts, and by testing it out I actually mean cut 4 of offcuts to form a rectangle as one thing I would consistantly get wrong in my head was which way the angle needed to be 🙂 When I was making up my outside table I actually made timber templates for the legs and still messed it up! Outdoor table build

Offcuts cost nothing and practice makes life much easier.

With the chock, I woudl remove it before you nail the others home, just to see if there is any play in the stained glass really, no other reason.

Dave

https://www.workshop.bunnings.com.au/discussion/comment/54106#Comment_54106

Hi @EricL

Re the timber screws, is it possible I could use some of my many leftover macsim stainless steel T25 star drive 10G-10 x 50mm screws, or would they be too soft? I still have the 'clever tool' they came with, or I could just use a standard drill bit? What size drill bit would you recommend? I can't find these decking screws on the Bunnings site anymore...

Macsim 17SSCBRX1050U

Thanks,
Jason

JacobZ

https://www.workshop.bunnings.com.au/discussion/comment/89289#Comment_89289

Hi Jason (@BoeingFan),

Yes, those screws would be perfectly acceptable for this application, you'd just want to make sure to predrill and apply pressure when driving them in, as you seem to be aware, stainless-steel screws can be a bit soft.

The "Clever Tool" would be perfectly fine for predrilling, and it would add a nice countersink for the screw heads to sit in.

You could also use a standard drill, but with a separate countersink bit to achieve the same result. You want a drill bit that is roughly the same diameter as the shank, but smaller than the thread. This allows space for the screw to drive into the timber while still cutting in to get the holding forced. You'd have to compare the drill bit to the screw to be certain, but a 3mm drill bit is usually about right for pilot holes for decking screws.

Let me know if you have any further questions.

Jacob

https://www.workshop.bunnings.com.au/discussion/comment/110429#Comment_110429

Hi @JacobZ

Thanks for your reply. Yep, I think I'm 'burnt' enough with those stainless steel screws to skip them, thinking about it more. I'm going to grab the Zenith 8 - 10x50mm timber screws (that's a very confusing name to me), because the width of the stained glass window frame is 30mm, so I hope 20mm into the hardwood will be sufficient to hold it so I can remove the chocks, and, for the new exterior frame I'll be screwing through 19mm hardwood, then cement sheet, then hardwood studs, so I think the 50mm will be a great choice.

Cheers,

Jason

https://www.workshop.bunnings.com.au/discussion/comment/54242#Comment_54242

Well, we are halfway done...

I had to remove a 4m downpipe, add some Brutus cover trim, clean down and paint the undercoat on the raw fibro, then I caulked all around the window before working on the external frame.

We had some old timber from a door frame that I did a test run on for the 45º cuts, and the other half decided it worked well enough to stick with. So now all the gaps are covered until we get time to unscrew it, sand and paint it, then reinstall and caulk it. Hopefully that will happen on Tuesday.

Next thing I need to learn is how to fix broken fibro such as the hole at the top left of the window shown here. Also, those Brutus trim's bring a question to mind, as someone who lives in a 'bushfire prone zone' (thanks Council and insurance companies), I think that these will just melt and provide no benefit at all, am I right? My house really is a dogs breakfast, but I'm learning bit by bit and making improvements as I can afford to.

Thank you all for your help thus far 🙂

Jason

JacobZ

Hi Jason (@BoeingFan),

Nice work so far, those mitres look good.

I'm excited to see how it is once it is finished.

Thank you for the update.

Jacob

https://www.workshop.bunnings.com.au/discussion/comment/54106#Comment_54106

G'day @EricL

I got my other half to pick up a click and collect order for me yesterday which contained a can of the Parfix 340g Expanding Foam Filler (though some mongrel had nicked the nozzle so I can't use it til I get back to town on Friday!) and I noticed on the back of the can it says 'extremely flammable'. I'm wondering if that is only until it cures, or even after it cures?

If it remains extremely flammable, is there another competing product such as Sika 500ml Boom Expanding Foam Filler less flammable? Living in a bush fire prone zone is a pain in the dairy air (another reason why I always use hardwood over pine).

Cheers,

Jason

https://www.workshop.bunnings.com.au/discussion/comment/89429#Comment_89429

Hi @BoeingFan (Jason)

If you are after a fire-resistant expanding foam, I suggest using the Sika Boom Foam Expanding Fire Rated PU 750ml it is a 1-part, fire resistant, self-expanding polyurethane foam, which meets fire resistance requirements up to 180 minutes according to AS1530.4. Please note that this product will need to be specially ordered at the special orders desk and is subject to availability.

However, in regards to the regular expanding foam it is generally considered less flammable than when it's wet and curing, it's not entirely non-flammable. After curing, it becomes more fire-resistant, but it can still ignite under high heat or direct flame exposure. It would be best to cover it up with the timber trim for extra protection.

If you need further assistance, please let me know.

Eric

https://www.workshop.bunnings.com.au/discussion/comment/110505#Comment_110505

G'day @EricL (Eric),

Thanks so much, that's an option I feel more comfortable with. I'm not far from finishing the window project, though I need to order a new fibro panel for delivery to wrap this project up (and a new front door whilst I'm at it) so I've ordered the fire rated Sika on eBay to arrive on Tuesday.

As always, I'm grateful for your help.

Thanks,

Jason

https://www.workshop.bunnings.com.au/discussion/comment/122632#Comment_122632

Hi @BoeingFan (Jason)

Please make sure to post a photo of the window once you've placed the trim around it. I'm sure our members will be keen to see what it looks like.

Eric

https://www.workshop.bunnings.com.au/discussion/comment/130487#Comment_130487

Good Evening @BoeingFan

Just as an option with that hole in the fibro, how about installing an extra piece of timber across teh top of the window, kind of like a header that overlaps the window both sides, covering the hole in the process? Silastic it as you install so the top and side is waterproof around the hole and you may get away not having to replace the fibro 🙂

Dave

https://www.workshop.bunnings.com.au/discussion/comment/135357#Comment_135357

G'day @Dave-1 (Dave),

You've piqued my interest with that line of thought. From the bottom of the grey horizontal brutus fibro trim, to the bottom of the top horizontal window frame piece, it is 180mm. At minimum, I'd need a 500mm piece of wood to make it cover the fibro gap and be balanced across the top of the window. The challenge is that the fibro gap drops down below the top edge of the external frame...

I could glue a piece of timber using the construction adhesive to cover the remaining gap, and balance it on the other side. Alternatively, I could get a deeper (top to bottom, ie over 180mm) single piece of timber and cut out where the window frame is on the bottom side, to create a one piece addition. Much like a [ that is rotated clockwise 90º. The only other option we've thought of is to cut out another piece of fibro to match the gap and glue and nail it into place, then do the final frame caulk to make it water tight. What do you think?

I ordered from Starlink their $19 cable routing kit to make a nice neat cable route through the wall as well, which I'll need once this fibro gap is filled.

https://www.workshop.bunnings.com.au/discussion/comment/138616#Comment_138616

That cable routing kit looks great. I'm putting my vote to the extended piece of timber at the top. I also propose moving your internet cable below the window (close to the floor if possible) so that it does not interfere with the overall look of your window.

Eric

https://www.workshop.bunnings.com.au/discussion/comment/140783#Comment_140783

Evening @BoeingFan

I agree with @EricL on moving the starlink cable if possible. And here is what I was meaning with the thicker timber trim added to the top and bottom of the window (to make it match) I was thinking Merbau, which comes in 90mm and I think 180mm? or 190mm? Its just as a cover overt the hole so nothing gets in. The small bit thats left, you could do what you were suggesting with a piece of fibro or use the Sika Foam that @EricL suggested.

The purple is merbau, probarly the 180mm ish thickness.

Dave

https://www.workshop.bunnings.com.au/discussion/comment/142383#Comment_142383

Hi All,

I'm happy with the status of the window frame; for now it is finished. Thank you all so much for your help and advice, I couldn't have done it without your guidance. Next project is a new front door, then the following project is steps off our back deck.

Cheers,
Jason

Before Before

After After

JacobZ

https://www.workshop.bunnings.com.au/discussion/comment/143531#Comment_143531

Nice work @BoeingFan!

I'm glad to see it complete with some fresh paint to top everything off.

On to the next one, hey.

Jacob

https://www.workshop.bunnings.com.au/discussion/comment/144401#Comment_144401

Hi @JacobZ

Finally put the deck back together today, so I thought I'd add another picture to see more context of the window and where it's located. The steps that I've mentioned are the second next project, are going to go from the middle of the deck in the photo out to the right hand side where the little frog is against the post.

Pay no attention to the tools and stuff packed up inside the double glass doors, that's a downside of living in renovations!

https://www.workshop.bunnings.com.au/discussion/comment/145034#Comment_145034

Hello @BoeingFan (Jason)

That window looks fantastic! The trim has given it a very nice finish and now looks like a picture frame. I did not realize that you had a deck there and it just looks wonderful. It must be so nice to sit outside with a warm drink in your hand and watch the stars roll by.

Eric