Door Frame 8x2?

[MrsGarner]

Good Morning DIY Not Guru's


I wonder if one of you lovely people can offer me some advice.


We are finishing off (soonish hopefully) a house extension, we are torn between my father in law who purportedly knows everything to asking Google - but somethings we are just not sure of.


We have recently studded a wall (in order to hide heating pipes) the wall is breeze block plus CLS plus plasterborard making the overall width of the wall around 7.5inches.


The wall has a door way in it so I need to add in a door frame which will add a small lip for the plasterer to plaster upto and I thought ok great 8 x 2 wood and sorted. However I cant seem find anything in softwood unteated.


My question is would it be reasonable to buy some treated timber and use that? will it paint ok? Or should we look to glue 2 lots of 4x2 together? (we did this upstair when my FIL made a mistake and bought 3x2 instead of 4x2? and not sure im happy with the end result)


Or have I totally missed the plot and is there a much more viable option?


Thanks in advance

Louise

 

[Doggit]

8x2 is quite thick, and a normal door frame would be 32mm thick; also, it won't actually be 8" wide, as that's the preplaned size, not the finished size, so you need 4+5, and then plane it down.

Do you have the ability to trim it once you've glued the bits together. I'd consider getting 2 ready made door frames, and glueing them together. If you haven't got the necessary tools, then a local woodyard would trim them down for you. But it's also possibe that the woodyard would prepare the 9x2 for you.

 

[MrsGarner]

Sorry I sent this from work and got it all round my neck!

The block width is 4in and the cls plus plasterboard is 2in.

So ideally I'd need 6.5x2 I think which doesn't exist (I don't think)

Should i still look to glue 2 bits together?
Thanks for your time (and patience)
Louise

 

[Doggit]

You need to remember that planed wood comes out less than the stated sizes, so 7x1 comes out at 6.75, and normally 22mm thick. And door frames are normally 32mm thick, (1.25) but as you don't have the equipment to trim and plane the glued wood, you idealy need to go and have a chat with your local woodyards, and see what they can knock up for you. They won't often charge too much for the extra work, but you'll have a finish that you're happy with.

 

[foxhole]

Have used 25mm mdf in the past , diy sheds that have cutting machine will rip it down to exact width.

 

[Doggit]

MDF is okay as long as you have some solid wood behind where the hinge screws are going to go

 

[foxhole]

MDF is okay as long as you have some solid wood behind where the hinge screws are going to go

Never had a problem getting a good fix into mdf.

 

[Doggit]

It's a time thing. It may well last 10 years - or only 12 months if there's kids slamming the doors. But the real problem, is trying to fix it when it does go.

You're okay at these things Foxhole, but someone inexperienced can overtighten the screws, and and then they've completely donald ducked it. They'll also find it more difficult to get a good recess for the hinge.

 

[MrsGarner]

Thanks. I'll pop down to the wood yard I normally use tomorrow and have a chat.

Thanks for your help!!

 

[foxhole]

It's a time thing. It may well last 10 years - or only 12 months if there's kids slamming the doors. But the real problem, is trying to fix it when it does go.

You're okay at these things Foxhole, but someone inexperienced can overtighten the screws, and and then they've completely donald ducked it. They'll also find it more difficult to get a good recess for the hinge.

You would struggle to over tighten a screw in 25mm mdf even with an impact driver , it's also much easier to cut a hinge recess in mdf than timber.

 

[Doggit]

Okay Foxhole, I can see where you're coming from; and they're fair points.

 

[Deleted member 174758]

Just to say, 8 x 2in is going to be potentially unstable with a tendency to cup over time. It is available in joinery grades, but it is hugely expensive relative to the cost of a standard casing and limning. Far better IMHO to ho for conventional casing with a lining to extend the depth:

This is a very traditional approach to the problem. As to MDF casings/linings - they work well and are often used in commercial builds these days. Part of the strength in them comes from the fact that you foam them in all round, effectively "glueing" them into the building (this is actually done for fire-rating purposes). They hold pretty heavy doors, but as ever choosing decent quality screws with a deep thread and good hinges (we invariably use stainless steel fire door hinges which are a lot thicker than cheap bent steel domestic hinges) is key to getting it all to work.