Making an external door from MDF

[MattRoberts]

Hi all, this may well be a bad idea, which is why I wanted to float it here first.

I'd like to replace my UPVC front door with a new one. I've looked at composite doors, but it's looking like nigh on a grand to replace the door, frame and side window panel.

As an alternative, I'm considering making my own using the measurements of the existing door as a template, and simply putting it in place of the current one (re- using the hinges, lock etc).

The current one is 44mm thick, so I was planning on sandwiching an 8mm core between two sheets of 18mm MR MDF, and using weather shield paint. Is this a really bad idea?

I'm also concerned about the edges not being as durable - should I edge the door with a hardwood?

Thanks for any tips.

 

[LancsRick]

Ok I'll wade in on this one. Why are you changing it?

If it's for looks, then ok, go for it. If it's for security, then you can't beat composite. If it's not those, then why?

 

[Jamied]

I don't mean to be negative on your cost saving idea, but I personally think its a very bad idea.
Moisture will penetrate through the weather shield paint and the MDF will blow .
Also any villain could easily access your home with a slight kick to the door.
I would be looking at the second hand market if you need to keep costs down.

 

[Jamied]

I don't mean to be negative on your cost saving idea, but I personally think its a very bad idea.
Moisture will penetrate through the weather shield paint and the MDF will blow .
Also any villain could easily access your home with a slight kick to the door.
I would be looking at the second hand market if you need to keep costs down.

 

[ColeyS1]

Tricoya would be the most suitable sheet material but it £140 ish for an 18mm thick 8 x 4ft sheet.
This picture might be of interest.

Fully submerged for a couple days. On the left is external mdf (roughly £40 a sheet) vs moisture resistant mdf on the right. Both of them swelled considerably (tricoya wouldnt) but for not much more money the external mdf is a lot better.
Will the door be in a porch or under shelter? What about painting it ? A guy on the 'linseed paint thread' seemed to think it looked reasonable.

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[LancsRick]

Coley your picture hasn't posted matey.

 

[MattRoberts]

Ok I'll wade in on this one. Why are you changing it?

If it's for looks, then ok, go for it. If it's for security, then you can't beat composite. If it's not those, then why?

For looks. The current one has a large bit of glazing with horrible mottled privacy glass, and it's marked by the previous owners. It just looks a bit naff

 

[MattRoberts]

I don't mean to be negative on your cost saving idea, but I personally think its a very bad idea.
Moisture will penetrate through the weather shield paint and the MDF will blow .
Also any villain could easily access your home with a slight kick to the door.
I would be looking at the second hand market if you need to keep costs down.

I appreciate your points, but I'd like to think that a 44mm thick door would be a bit stronger than that! I'd also be reusing the current door's locking system which has multiple bolts along the length.

The door is quite shielded from the elements, and I've not noticed it being soaked, even when there's heavy rain. That's not to say that moisture during the winter won't penetrate though - I had hoped the weather shield would prevent that, but perhaps not

 

[MattRoberts]

Tricoya would be the most suitable sheet material but it £140 ish for an 18mm thick 8 x 4ft sheet.
This picture might be of interest.

Fully submerged for a couple days. On the left is external mdf (roughly £40 a sheet) vs moisture resistant mdf on the right. Both of them swelled considerably (tricoya wouldnt) but for not much more money the external mdf is a lot better.
Will the door be in a porch or under shelter? What about painting it ? A guy on the 'linseed paint thread' seemed to think it looked reasonable.

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Thanks for the info. External MDF does indeed look like a better option. I think if the MDF idea is a no goer, I'd probably just look to go for a composite door instead, and paint the frame and side window.

 

[Sheffield Tony]

I think that replacing an exterior door comes under the auspices of building regs, if that worries you. For a wooden door, there is a minimum density specified that implies hardwood, Iroko is just OK.

I struggle to imagine how bad a door - or anything else for that matter - would need to be before MDF is a superior replacement.

 

[MattRoberts]

Sounds like the consensus is that it's a bad idea! Thanks for the advice chaps!

 

[screwpainting]

I re-skinned a metal garage up and over door in Tricoya mdf a while ago. the reason being i could not see anything i liked off the shelf for under three grandish and i like to design my own stuff. I screwed and glued a new skin of 6mm to the metal door then used 12mm to create a framed/panel effect that I stuck onto the 6mm with resin W. this was primed with little green aluminum primer then painted with their exterior satin which was a joy to use and looked fantastic. This door will very seldom if ever need to be opened and gets very little wear and tear but is in direct sun in the morning plus cops any rain etc full on. I routed all the edges of the false panel components with an Ogee profile so it has loads of sharp edges. This was far from and ideal for the paint ,but, the only problem I have found is that where I actually used six screws to fix the bottom rail to the 6mm back board, they have started rusting through (didn't use stainless) under the paint and I will have to take them out and fill and repaint now they have done their job. Apart from that, the Tricoya has worked brilliantly, all the routed edges look excellent and so far the original up and over mechanism has handled all the extra weight. So for my little project I recon it was a resounding success, if a little unorthodox and probably all wrong. I'll try and stick up a pic tomorrow as its hard to describe.
For a new complete side hinged door that was going to be opened and closed a lot in a high traffic area, I don't think the structure of Tricoya is robust enough and would worry that the fittings would tear out after normal use, slamming etc. Plus not sure how the hinging would work or hold up.
Just my two bobs worth.

 

[ColeyS1]

Sounds like the consensus is that it's a bad idea! Thanks for the advice chaps!

I wouldn't be so hasty, depending on your design. This was my first experiment with tricoya.

I think the openings around a metre...possibly a bit more wide. That was 18mm tricoya with 18mm false stiles just stuck on the back to look the part. It's a stable door so gets left open and used quite often.
When you mention upvc I immediately thought 4 inch stiles/rails with a massive pane of glass in the middle. I don't think a narrow mdf/tricoya frame would be strong enough. If however it had a big panel in the bottom with a pane of glass in the top (from one big piece of wood) in theory I can't see why that wouldn't work. Is it worth a gamble, perhaps a day or so of making and priming to see if it'd work? Worse case scenario you've wasted a sheet and your time and you just screw the old one back on.
Have you got any pictures of what you were thinking of making ?

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[johnnyb]

I didn't think there was any regs concerning the type of material front doors are made off. I've made many fronts from Douglas fir. Secondhand is a good option if cost is tight because many quality doors were made in the past. If your openings standard size look around reclamation yards.

 

[ColeyS1]

I've seen some proper garbage off the shelf front doors. Poorly dowelled together, peeling veneers etc.

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[Sheffield Tony]

I didn't think there was any regs concerning the type of material front doors are made off. I've made many fronts from Douglas fir.

Since 2015. Part Q, Appendix B - Bespoke timber secure doorsets. Should be manufactures from solid or laminated timber of density at least 600 kg/cubic metre. Also specifies minimum thickness for panels, width of stiles, width of panels, locking, letterplates etc. Applies to garage doors too, if they permit access to the dwelling.

 

[Spragnut]

Keep a look out on eBay, we purchased a second hand, like new, composite door from there for around £100, seller was replacing it for a different colour composite door. It was only a year old!

Don't think he realised what he was selling was composite to be honest, I think it was listed as upvc door, but I could tell by the pictures it was composite. And it was!

Anyway definite bargain, and lots to be had if you keep an eye on eBay, just make sure your buying composite and not upvc that someone has mis listed.

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[Doug71]

I didn't think there was any regs concerning the type of material front doors are made off. I've made many fronts from Douglas fir.

Since 2015. Part Q, Appendix B - Bespoke timber secure doorsets. Should be manufactures from solid or laminated timber of density at least 600 kg/cubic metre. Also specifies minimum thickness for panels, width of stiles, width of panels, locking, letterplates etc. Applies to garage doors too, if they permit access to the dwelling.

I think that only applies when you are forming a new dwelling, new build, conversion etc. Think different regs apply when it's a replacement, refurbishment or extension.

Doug

 

[ED65]

For looks. The current one has a large bit of glazing with horrible mottled privacy glass, and it's marked by the previous owners. It just looks a bit naff

How about painting the PVC? There are specialised uPVC primers but some sources say that shellac will do.

And presumably you can replace the glass panel with one more to your liking. I don't know if every door allows this but it is possible, so that if the glass gets cracked you don't have to buy a whole new door!

 

[Lons]

I didn't think there was any regs concerning the type of material front doors are made off. I've made many fronts from Douglas fir.

Since 2015. Part Q, Appendix B - Bespoke timber secure doorsets. Should be manufactures from solid or laminated timber of density at least 600 kg/cubic metre. Also specifies minimum thickness for panels, width of stiles, width of panels, locking, letterplates etc. Applies to garage doors too, if they permit access to the dwelling.

I think that only applies when you are forming a new dwelling, new build, conversion etc. Think different regs apply when it's a replacement, refurbishment or extension.

Doug

My understanding if memory is correct is that unless you use a FENSA installer you would usually need to submit a building notice and pay appropriate fee to obtain a completion certificate. As stated already the regs include doors constructed from any material but I doubt that MDF would be considered suitable.

Nothing to stop you putting whatever door you like on your house but you could have problems when you try to sell without compliance unless you could somehow suggest it had been fitted before you moved in,
As an aside, your insurance company could refuse to pay out if they thought your door was not standard or secure enough, even if burglars gained entry via a window. Something to think about!

As suggested, worth keeping an eye open for s/h but also worth talking to local manufacturers, the one I used as my main supplier always had a surprising number of new doors which were very slightly marked or been ordered wrong size. I bought a composite for my own rear extension for £100 + VAT though that was a few years ago.

Bob