Need to fit 10 new doors - should I go with mdf or soft wood casing?

Simplez said:

For Howdens don't I need a trade account?

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Yes you need trade account but it isn't difficult to "convince" them that you are trade. Just fake a letterhead. That said if you know a builder/etc with an account they might get a better discount than you.

Over the years< i have used Todd Doors quite a bit. They are local to me but IIRC they have website and will deliver nation wide.

opps said:

As a decorator I absolutely hate pre-primed MDF. The primer normally needs so much sanding that I end up having to pretty much sand it back to the bare MDF, particularly on routed edges.

MDF architraves in areas of high traffic are far less forgiving than timber. If the owner/tenant is fairly clumsy, MDF will be more difficult to re-fill and sand.

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Don't wanna teach you your job, but my decorator goes straight on the primed mdf with undercoat, then white gloss and the results are astonishing.
Clumsy tenants will destroy whatever you put there, even stainless steel.

As mrrusty says the terms get used interchangeably but (in my area at least) a lining is about an inch thickness whilst a casing is made from 4x3 timber with jamb rebated out.

mrrusty said:

Probably start a bunfight but these terms get interchanged frequently. In my book a "lining" is a plain timber where the door stop is separate and fitted afterwards, and a casing is a frame with a pre-machined stop. There are advantages and disadvantages with both. If you have nice straight walls and everything is square, use casings - fewer joints. If you have slightly wonky walls etc, using linings allows you to adjust the stop to suit, and gives a bit more flexibility. Personally, I usually just use pre-formed casings from the merchants e.g. https://www.cwberry.com/Building-Ma...ternal-Standard-Door-Casing-Set_M01090381.htm

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Thanks for that - that seems a good price - I was looking at paying £25 plus per casing.

The walls once plastered will hopefully be straight - so casings will be less work and easier to fit?

that seems a good price

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Y good merchant, however like all softwood you do really have to go and select yourself if you want nice straight, shake-free because the quality of softwood is not that great anywhere

mrrusty said:

Y good merchant, however like all softwood you do really have to go and select yourself if you want nice straight, shake-free because the quality of softwood is not that great anywhere

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Hmm I was thinking of ordering them online. I may have to get an idea of prices online and then swing by the merchants and see what they will offer.

Thanks for your advice - really appreciated.

swing by the merchants and see what they will offer

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Always best if you can. If it's a load of stuff like floorboards you can usually juggle things so the poorer pieces don't matter, but a casing with a twist in it is a PITA.

Another thought.

Do you know the size of the opening's in the walls?
For UK door sizes forget about metric measurements - UK standard internal doors are 26 inch or 28 inch or 30 inch, infrequently 32 inch. Most common are 26 or 28 inch. That is why you end with odd metric sizes in the DIY barns - cause they are not supposed to quote sizes in imperial. Builders merchants will expect either imperial or metric and be able to supply sizes as ordered. Knowing the difference between door size and the wall aperture will dictate casing or lining required.

wgt52 said:

UK standard internal doors are 26 inch or 28 inch or 30 inch,

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or even 24", 27", 30" 33"

johnny2007 said:

Don't wanna teach you your job, but my decorator goes straight on the primed mdf with undercoat, then white gloss and the results are astonishing.

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I specialised in painting MDF cabinets for about 20 years. Like the timber merchants, I used to use waterbased primer but I did so knowing that I would have to sand it back to the point where you could hardly see the primer anymore.

Contrary to popular belief, the surface of MDF is not smooth. It has a "grain", I assume, the result of wide drum sanders used in the final stages of manufacture. That grain and the fibres swell up when primed with waterbased paints.

I do not want to malign your decorator but it seems that we are trying to achieve very different standards of finish. I can only assume that we are working to different budgets and time constraints.

The following photo is an example of a worktop that I have primed with acrylic primer and then started to sand flat with 220 grit mesh. You can clearly see the "grain". -edit, it seems that this site compresses images- follow this link- https://1drv.ms/u/s!ApkFchP_5QLajd01fTLCNEh00jnibw zoom in to the left hand side of the sander and you will see evidence of parallel grooves



In the above, I used a roller to apply the primer, not something I like doing but I had run low on my supply of Anza paint pads and wanted to save them for the oil based eggshell.

The following image of a MDF shaker door shows the raised particle/grain after priming with waterbased primer. That is what the MDF architrave would look like if sanded first. -edit link- https://1drv.ms/u/s!ApkFchP_5QLajdo-BAnsuvtNOdfLbw



I am to achieve a hand painted finish that looks like it was sprayed and then someone brushed a very thin coat. You can't get tht kind of finish if you just apply one undercoat and one finish coat. I guess in theory you could apply 5 coats of oil based undercoat and sand that flat without going through the waterbased primer but that will take much longer.

opps said:

-edit, it seems that this site compresses images

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If you (I) click on the small pic, it will open a large one.

Which will then enlarge further if you (I) click on the top right arrow, and then on the pic.

All well and good, but somehow my decorator is not one to do a half decent job, he's one of them who goes around with a number 1 artist brush once he's finished to make it perfect.
His white gloss looks sprayed (2 coats after undercoat btw), not a sign of brushmark in sight.
That's why when I found him, I left all my decorating tools in the large drawer in my workshop and never touched them again.
I think it's a matter of "hand", i have tried his same technique, same products, even same brushes, but the results are not the same.

JohnD said:

If you (I) click on the small pic, it will open a large one.

Which will then enlarge further if you (I) click on the top right arrow, and then on the pic.

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I may have been wrong about the compression. Tnx

johnny2007 said:

All well and good, but somehow my decorator is not one to do a half decent job, he's one of them who goes around with a number 1 artist brush once he's finished to make it perfect.
His white gloss looks sprayed (2 coats after undercoat btw), not a sign of brushmark in sight.
That's why when I found him, I left all my decorating tools in the large drawer in my workshop and never touched them again.
I think it's a matter of "hand", i have tried his same technique, same products, even same brushes, but the results are not the same.

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Sorry Johnny, I have often agreed with the advice that you have given on this site. I do not believe that you can obtain a high quality finish on an inferior product unless you either apply a lot of paint (and then sand the paint flat) or sand the original product flat.

I am stupidly busy at the moment but I would be willing, at some point in the future to post you some samples of painted MDF to compare and contrast. I will send you MDF that I am happy to sign off on and some that hadn't been sanded.

Sorry mate, I am not trying to be combative but I have only ever once been impressed by another decorator who painted MDF and that was when I worked for Kirsty McColl and she has been dead for years.

Wasn't arguing.
Most likely if I saw your finish I would find another standard.