Advice please in fitting external door frames

[AJB Temple]

I have a pair of double doors and a single oak door to fit in my new kitchen. The frames are oak and will end op with a PolyX finish I expect. The floor is presently concrete but will have underfloor heating and limestone slab on the inside and some sort of stone paving outside. One door frame is quite protected inside an open porch. The other is exposed to rain.

Obviously I need to allow for the thickness. My question is what should I put under the frames? Both have a drip line and I am presuming that best practice is to leave this clear of the surrounding finished ground level?

Should put a strip of DPM under each frame?

Should I bed them on a strip of slate?

I've fitted dozens of internal doors but never an external one to my house.

 

[AJB Temple]

Surprised no one has any thoughts on this. Will have to resort to you tube which is unreliable for good advice.

 

[Trevanion]

It's one of those jobs that has a million answers but no actual be-all-end-all answer, Some will tell you to put the frame in and ram oakum in the gaps, some will tell you that you need to DPM around the whole frame, some will even tell you not to bother with a door and just bare the natural elements

I personally just bed the frame down onto the cill (Slate, Concrete, whatever it is) with silicone, fix the hinge side to the wall nice and plumb and fit the door with the lockside of the frame loose to get the fit between the door and the frame absolutely spot on and then fix the lock side of the frame. Bit of squirty foam around the sides and top of the frame and leave the rest to the builder.

Although a lot of people will tell you that's the wrong way to do it, but they won't present a case for what's totally correct.

(I think this thread may have got missed originally because it was posted into someone else's thread rather than it's own thread)

 

[johnf]

You should have a dpc below the frame stops the rising damp rotting the frame

 

[RobinBHM]

Cill: generally just sit it on dpc.

Tip: if your screed is butting up against the back of the frame, keep it separated with expansion foam. And keep gap on final floor finish -or underfloor heating will expand the screed and push out the door frame.

Sides: no vertical dpc needed if cavity closures fitted.

When fitting door frames, wedge door frame in place, then fit door in frame on hinges. Adjust frame until head of frame has even margin across head. Then move jambs in/out as needed to get door sitting nice and flat to frame -ie frame not twisted.

 

[AJB Temple]

Thanks. Super helpful. I have made the frame in oak to fit a lovely old reclaimed door. The frame is fully assembled, glued and screwed and is dead on square and zero twist.

My next problem is the bricky who did the block-work for me, has made the door opening about 30mm too wide, despite me providing an accurate drawing. This is not a big deal as I will be rendering the wall anyway. I think I may as well put dpm all round. My thought was to use a couple of strips of oak to make the frame wider to fit the opening. I can fit these to the opening or the frame I suppose. They will be hidden by the render.