Thread: Door triming and installation

Is your measurement of 25mm the full thickness of the door or just the stile, being the vertical solid timber sandwiched between the hardboard sides? I haven't seen 25mm as a full thickness in off the shelf external doors. Standard internal and external door full thickness is 35mm, being 27mm stiles and rails plus two faces at 4mm each, although there are thicker off the shelf external doors.

Assuming your door is a hollow core and standard thickness of 35mm with 27mm stiles, it's not ideal but, yes, you can take 6.5 - 7 mm off each side if you accept that this will void the manufacturer's warranty if the manufacturer states maximum 3mm off. It's your problem if the door fails in future. Some manufacturers in the past and maybe now stated maximum trim of 5mm each side, so an extra 1.5 - 2mm each side isn't massive.

You might encounter problems with the lock block, which is a piece of solid timber usually in the middle of the door on the lock side. Depending on how generous the manufacturer has been with the depth of the block from the edge, when you drill your hole for the handle you might go outside the block. From a practical point of view this doesn't matter much as long as you don't deform the unsupported faces by over tightening a horizontal lock screw outside the lock block . If the screws are vertical this shouldn't be an issue as they should be supported by the lock block.

Hollow core doors are held together as much by the honeycomb interior glued to the faces as by the stiles and rails. I've worked on old doors that have been trimmed much more than you're doing and a few with missing bottom rails and they've held together alright for years.

The surest way to cause a painted exterior door to die prematurely is to ignore the manufacturer's instructions to seal the top and bottom rails, which many people fail to do. You can get away with it on internal doors and it's commonly done, but not on external doors.

All that said, you'd be a lot better off returning the door to Bunnings and ordering a custom made right size door which doesn't require trimming. It'll cost more but in the short and long runs it's worth it for avoiding trimming the door and keeping your warranty.

Bunnings might still offer a reasonably priced installation service if you buy the door from them. I say it is / was reasonably priced because Bunnings' contractor (Grey Army) approached me a couple of years ago to install Bunnings' doors. I think Bunnings charged customers $120 and I would have got $60. It didn't proceed, not least because I got a lot more than $120 for door swaps, never mind a lousy $60.

Take it back, get a refund and then order one to your specific size.

Thanks for the reply.

The door thickness is 35mm. Its the stile that I am talking about.

Bunnings fitting is $300 - I asked. More than twice the price of the door + door knob + hinges (oh and delivery!. (I asked)
It is an external door (so even though they say solid I think its "pretend solid"

I am happy with voiding the warranty in this instance as it will only serve as an entry point for the man cave. Its not a fort knox building.

The most important thing for me here is to make sure that its sealed and painted well and good as it will be open to the elements.




Thanks
N

Originally Posted by NicA

It is an external door (so even though they say solid I think its "pretend solid"

The grades of door, starting from the bottom in structure and price, are hollow core, solid core and solid.

Solid is solid timber all the way through, but usually made up from different strips and or panels of timber as a single slab would be very expensive.

Solid core and hollow core look the same from the outside as both have hardboard faces glued to visible rails and stiles, but hollow core has honeycomb core and is mostly voids where solid core has solid timber core made up of small pieces of timber glued together. So yours would be solid core. You can tell by the significant difference in weight between a hollow and solid core door.

Solid core is supposed to be more stable than hollow core.

If I was asked to install this door, I would be confident in trimming 7mm off each side. Might be different with a hollow door as there is less for the hinge screws to grip.
If a solid door might require a second person, even semi solid is heavy enough.

My price to install would be about $200 - about 3 hours labor. Painting is extra.
Best to pre trim and paint all sides before installing.

Originally Posted by Handyjack

If I was asked to install this door, I would be confident in trimming 7mm off each side. Might be different with a hollow door as there is less for the hinge screws to grip.

Agree. My original post assumed it was a hollow core.

Originally Posted by Handyjack

My price to install would be about $200 - about 3 hours labor.

I'd charge about $220 - $300 depending on how square the jamb is and whether I have to trim the new door out of square and or fix the jamb and whether it's a simple handle or a handle and separate deadlock. I'm about the same time for labour. I always reckon I should be able to do it in 2 hours but it almost always runs out to about 3 hours, sometimes more.

Originally Posted by Handyjack

Painting is extra.

Same. I encourage customers to paint it themselves as the time involved in just two coats with usually dead drying time in between or two visits fitted in to other work makes it unduly expensive if I do it.

Originally Posted by Handyjack

Best to pre trim and paint all sides before installing.

That's the best way to do it. Drying time isn't an issue as it's a small thin area that can be force dried with a heat gun in 5 to 10 minutes per coat, so the extra cost to the customer is money well spent in not having to do it themselves and ensuring long life for the door.