# When to Install Pre-Hung Interior Doors For New Construction



## Hages

I am building a home and I am about to shoot PVA primer on the walls. No finished floors yet. First floor I need to put 3/4" plywood subfloor and vapor barrier to the concrete slab floor base. Second floor just needs the finished hardwood floors.

My question is when do I install the pre-hung interior doors? 
Before I do the floors I suppose?

Do I do the door casements before or after I paint the walls?

TIA


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## AtlanticWBConst.

Hages said:


> I am building a home and I am about to shoot PVA primer on the walls. No finished floors yet. First floor I need to put 3/4" plywood subfloor and vapor barrier to the concrete slab floor base. Second floor just needs the finished hardwood floors.
> My question is when do I install the pre-hung interior doors?
> Before I do the floors I suppose?


Definitely Install AFTER you do the floors.



Hages said:


> Do I do the door casements before or after I paint the walls?
> TIA


Definitely do the casing AFTER you prime the walls. It will make your life work alot easier. Do your Latex based Caulk or putty any cracks, spaces, etc. (esp. on your exterior edges of the casing where it meets the walls)..and then do your top coat of finished wall paint...


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## helpless handyman

Hi Alantic Construction, I am about to do the same. So your saying install the finished floor first, (hardwood), then install the prehung doors? Thanks


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## AtlanticWBConst.

helpless handyman said:


> Hi Alantic Construction, I am about to do the same. So your saying install the finished floor first, (hardwood), then install the prehung doors? Thanks


Absolutely the way to install....
In this order:

1.) Hardwood floors
2.) Doors and their casings.
3.) Baseboard.

This allows you to install your trim nice and cleanly....with casing and trim 'snug-tight' against your new hardwood floor....so it looks like you can't even fit a piece of paper through the trim and floor. It looks nice and 'custom finished'. Here's a picture of an example of this, on an addition we did last month:










(You can imagine how different the floor, casing and trim would look (where they meet each other)...if the floor were installed after....) Existing floor is on the lower side of the picture (with ugly HVAC vents)....new floor is on the upper side of the picture. Entry casing and baseboard were attached 'above' and 'over' both the new and old floors.... AFTER the new floor was installed.


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## AtlanticWBConst.

After thinking about the original question regarding PRE-HUNG doors as opposed to actual doors with separate jams/casings, &etc, I need to mention this:

...Pre-hung doors can pose an issue if the jams and the casings are not at the same height (flush) on the floor...which I know that they sometimes they aren't (Very likely if purchased from _'Large Home Stores'_ and thus, dependant on where purchased).

In that case, it can require more time and work to get the doors installed and to have the casing and jambs look 'seamless' against the new flooring.

There are these installation options:

1.) Install the pre-hung doors before the flooring. Use a "Japanese Flush-Cut Saw" and a scrap piece of the hardwood flooring (to match the flooring thickness) - and cut the jamb and casing depths out ...... to be able to 'slide' or 'fit' the hardwood flooring under these 'snuggly'....

2.) After the hardwood floor is installed: 'Lay' the pre-hung doors on a flat suface at waist height (for easier access to working on it) ... work surface: lay a sheet of plywood on top of saw horses. Concerned about scrapes? - Lay scrap carpet or other soft material over the plywood...
Measure and mark, then very carefully pre-cut the jambs and casings 'manually' (again, a Japanese flush cut saw is good for this) = Cut the jamb and casing 'flush/eve' with each-other, and then.... install the pre-hung door.

If done right & done carefully: these two options will work. (#1. is used on a regular basis for installing hardwood flooring in 'remodeling circumstances')

There is actually a powered saw (called a 'Jamb saw') that looks similar to a 'grinder' that is specifically designed and manufactured to cut out door jambs and casings prior to hardwood floor/other flooring installations. Most Hardwood flooring companies use them regularly....


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## helpless handyman

Thanks Atlantic, I figure Prehung doors would be easier for me to install. I am not a carpenter and doing the door jambs would probably be a big task. But then again I have renovated this house all by myself, and I completly gutted it out. I have all the sheetrock walls and ceilings installed, all the taping sanded and primed, and I'm proud of myself the way things look, you can't see any of the seams:thumbup:. The only thing I left the door opennings at 32 by 84, s/b 32 by 82. I was leaving enough room for the wood floors, I might have to install some sheetrock to cover the gap, any ideas on this? Do you think I will be able to tackle installing door jambs? Thanks By the way nice job on those floors!!!!


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