"Can I use the old door as a "template" of sorts as well?"

That's what I did. I have a home built in 1950, with maple door frames.

I purchased 6 panel doors, and sent the old doors (number the doors and door frames) to the cabinet shop, where they mortised the hinges and locks. Fit great.

When I did that sort of work, I charged much less to install a prehung than fit a slab to an existing frame.

Reason? Time.

The doors you have now were most probably prehung in the first place.

I've installed an old door that was 200# 8' tall and 46" wide in the rough opening in a new house. Built the frame(which meant installing those little shims) and fit the door. Took me the better part of the day. Had that door been a prehung, it would have been maybe 2 hours.

As Mac said,it take's about 3 or 4 times as long ( for experienced hanger) to hang slabs. So if you have time,hole saw,drill, router, chisels and screwdrivers,hanging interior slabs are pretty simple. You didn't ask but don't even think about exterior slabs,I've done them but it took all day and ever tool I owned.

Also if you visit a real lumberyard as opposed to a box store you will find a much better variety of sizes available to better fit your openings. And those dreaded shims are necessary not just because of door size.....

I definitely won't try exterior slabs. I wanted to go the slab route to save money. The extra cost of a prehung adds up to a lot once you get to more than a few doors. Plus having to remove and reinstall the casing, etc.

Will a real lumberyard also have prehung doors with varying jamb widths?

Absolutely, they generally either order the prehungs in from a millwork distributor or the larger ones have a shop where they hang them themselves but either way you can get virtually any jamb width necessary. They will take stock widths and rip them for you no issues there.

In the long run you really are not saving money if you put a value to your time.

"Will a real lumberyard also have prehung doors with varying jamb widths?"

Not many but they are set up with local door plants to get special sizes on short turn around. You can measure old jambs before removing them and then see what's available. Not to lead you out onto thin ice but if you see yourself doing much diy finish carpentry over coming years,a table saw will help immensely. In this case jambs or fillers could be ripped to width. I've done both and never had a customer say the results" look cheap or forced". In fact if jambs are painted,it's difficult if not impossible to see the filler. Clear coated natural jambs are challanging but certainly doable if filler material is carfully selected and finished. Other than fillers ripped on a table saw,a bottom bearing flush trim router bit is required. Custom fitting doors on site isn't something one would want to hire done except in unusual cases like a 17th century restoration or where material is exotic. Bottom line imo,if one doesn't injoy the satisfaction of diy,taking time to do it right is generally not in the cards.

I do enjoy it. I've done a lot of basic stuff, but not much with doors.

A table saw is on my "to buy" list, so that is a good thing.

The jambs will be painted.

I have more experience with buying table saws than I would like to admit. I bought three cheap($300 and down) table saws for my business before wising up and spending the minimum(10 years ago) $400 necessary to get a decent new TS.

The problem with the cheap saws are the fences, miter gauges, and the motors. All are substandard and create many more problems than should be experienced. I now have two mid price range saws, one portable and the other in my wood shop. Both cost more than $400, but less than $600, new and both are more than 10 years old and will last me the rest of my years.

Buying a cheap saw discourages the user and means having to buy a better one the next time. Plus, the better types have a better resale value than the $00.00 a cheap saw would bring.

"Buying a cheap saw discourages the user and means having to buy a better one the next time. Plus, the better types have a better resale value than the $00.00 a cheap saw would bring."

And would you agree injury is far more likly while useing cheap saws? I usually suggest newbies ask an experienced friend go with them saw shopping. There's no way of telling people everything to look for but experienced eyes know when they see it. I have a no name saw ( seriously,no tag and no evidence where one was removed) that looks and performs like an old Delta Contractor. I've used old Craftsmans that did pretty well but I wouldn't reccomend buying a new Craftsman.

Now,after a guy break's down and spends upward of $1k on a saw we can discuss why he should throw his big box hand plane in the scrap pile and consider ordering one for $200+.LOL

Just hung eight solid pine panel doors, with one left. Purchased a butt jig on Craig's list for 100, new they go for 250-300 (porter-cable). Already had router and bit, I would also get jack and fillet planes. I am not a pro builder , so there was a learning curve. First door 2-3 hours, the last door less than an hour. Each door total cost was 175 (hinges and lock set included). For the same money I could have purchased pre-hung, add 25 for lock set, using this type was not fit for the situation. Hardwood floors were installed after finish was done.

As far as tsaw goes , look on Craig's list.U can get an older quality saw for short money (belt driven w/ cast iron top). Still using dad's saw ,Craftsman purchased in 1952.

geoffrey_b - How much did they charge you to mortise the hinges and locks? And did you take them to any specific kind of cabinet maker?

They did mill work. I purchased the doors (from a catalog) from them. I don't remember what it cost - but it's well worth it.