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Rebuilding rotted out entry door threshold

strawmyers's picture

Rebuilding rotted out entry door threshold (post #207465)

There's a west-facing exterior door off of our living room that constantly gets pounded by rain/snow.  I knew there was a water infiltration issue because I've seen some water on the tile inside the door during rain with heavy winds.  Also, the aluminum threshold felt a bit spongy when I'd step on it.  This part of the house is an addition that the previous owners had put on probably 10-12 years ago.  We've been in the house about 1.5 years, now.  I bought a storm door this weekend to help block moisture from getting onto the sill.  Decided before putting the door up that I should investigate the spongy sill to make sure nothing needed done that would require me to have to take the storm door back off.  Took the aluminum sill off; and the wood under the sill and underlying subfloor were completed rotted out.  Same thing with the lower part of the door jamb once the alumimum flashing was removed.  Here's what it looked like once I cleaned out all of the rot:

  The thin strip of subfloor toward the front that isn't all rotted out is one I replaced over a year ago when addressing another water issue from a window next to the door.  You can see the two floor joists on either side of the middle cavity.  I need a sturdy base to build a properly-designed threshold off of; but without ripping up the tile to get to the adjacent floor joists.  I can't bridge across from underneith because the crawl space has been encapsulated with spray foam. 

  I'm very experienced with metal work; and have all of the asssociated tools (plasma, welders, etc).  I'm thinking about making a plate from 1/4" mild steel that can fill that space where the subfloor used to be.  It would be screwed to the two exposed joists, and have bracing on the underside that would keep the unsupported ends from ever going anywhere.  My thought is that this would allow me to adhere some 1/2" plywood to the 1/4" plate with construction adhesive to build it up even with the rest of the subfloor, then do a water-proofing sill tray (suresill?) on top of that and a new aluminum tray with composite material on the underside instead of wood.  Also need a new door jamb, obviously; but the questions regarding that will be in another thread to try to keep this on topic.  Thanks!


Straw (post #207465, reply #1 of 44)

Couple things.

You might want to just build this thread up from the bottom-Keep it all in this one.

New thresh, new jamb-how's the door?  If sound and you like it-what brand? 

Are you confident that the sub beneath the tile is sound?   Was there a sheet seam there b/4 or is that line of removed rot just a good attempt at a straight line?


A Great Place for Information, Comraderie, and a Sucker Punch.

Remodeling Contractor just outside the Glass City.


That's just a good attempt at (post #207465, reply #2 of 44)

That's just a good attempt at a straight line.  The subfloor under the tile on the left 2/3 shows that it has gotten wet; but is intact.  The right 1/3 is rotten to about 3-4" under the edge of the tile.  I put down 1/4" hardibacker before laying the tile; and that's probably the only thing supporting the outer 1/2 of the right tile.  Luckily its not in a location that gets stepped on.  There is a piece of 1/2" PT plywood under that rotten part (you can see it in the right-most bay of that top picture.  Could I take some concrete, mortor, or similar product and pack it under that corner to help support the tile?


The bottom right (hinge side) corner of the door is a little rotten; but nothing significant... nothing that merits the cost of a whole new door, IMO. 

I had thought about another prehung door if it needed replaced; but it would just come with the same all wood jamb.  I've been researching options and like the look of these Evermark frames with the finger jointed PVC lowers to prevent moisture wicking (the Everframe and ProCap).  Any opinions on these or a preferred alternative?


Here is the plastic sill pan I'm considering.  Any opinions on these or a preferred alternative?


I would like feedback on the 1/4" plate steel sub-subfloor outlined above.  I know it's not a standard approach; but I think it would work unless there's something I'm missing.  That is something I can get done after work one night this week so that I'm able to get to the "normal" threshold stuff this weekend.  I'll post the other questions in this same thread, as suggested, when the time comes.  They concern the storm door... so I'm not anywhere near that point, yet.  Thanks!

straw. (post #207465, reply #3 of 44)

I asked those questions for a reason-to further help figure the "whole" plan out.

Your steel idea will probably work at the area under the threashold, but there is reason to be concerned with supporting the tile also.  Maybe you could attach some more steel "wings/flanges" to the bottom of the plate you're going to lay under the thresh-they'd slip under that area of ply/cement bd./tile .  Maybe you only could get const. adhesive to slather on top of the steel and hope for a bond under that subfloor under the me-

Solid blocking would work, but unless you open up the outside of the box, don't know how you'd get that under there either.

There is a possibility of finding a complementary tile-pop up those at the door area-redo the subfloor and relay the new tile in a way that looks good, not patched in.


If you knew the door make-the it would be a good idea to find the supplier locally (fab'd the door frame) and purchase one of their new jambs-already equiped with a composite bottom to the threshold and Save-a-Frame/ Frame Saver or the same idea as you link to for the jamb sides.

These jambs are sized for the door by the fabber, the doors come from Thermatru, Stanley/Masonite, other.  The slabs are not all the same size from different manufacturers, so knowing the manufacturer is key.

You don't need to get the whole shebang-just the preassembled jamb/thresh with all new weatherstrip.  In many cases, you don't even need to do any if much mortising of the jamb for your existing door.

If you know the door will fit, get the jamb unmortised if that makes sense.


Get all the parts from a supplier and cut/assemble yourself.


As far as the parts you mention for the door-yes, they should have made them available a long time ago.  All or most have rotted whenever within earshot of water.  Here-FrameSaver is the ticket and supplied from most door fabbers.  The composite bottom thresh's are available from many places-get the adj. threshold for less trouble down the road.  At the same time-get a new bottom sweep for your door, since you'd like to keep it.

A premade sillpan, I've never used any-making my own out of peel and stick flashing.  There's some available that will stretch and form around corners.  However, cost of one sill pan v. roll of flex. flash?

I use quite a bit of the flex. flashing, so for me-it's the way to go.


One more thing.   Since you "might" replace the jamb now-can you raise up the unit so you have more room for a rug inside?  

and perhaps something for the storm to close to ?   I see edge of osb, but nothing else. 

A Great Place for Information, Comraderie, and a Sucker Punch.

Remodeling Contractor just outside the Glass City.


That PT plywood you see in (post #207465, reply #7 of 44)

That PT plywood you see in the right-most cavity actually extends under the unsupported tile.  Could I just squeeze construction adhesive into the void until no more will fit?  The space, by feel, is roughly 4"x3" x thickness of rotted subfloor (7/8").  That wood being under there is why I was wondering if it would be viable to just pack the area full of unused grout or concrete.  I has a partial bag of each in the garage, still.

As for the flex flashing to make a water-resistant sill pan, would it be okay to use peel and stick mastic?  I have a good bit of that left from sound deadening a home theater cabinet.  I imagine they're similar products???

Not sure who the door mfg is.  Only marks I found was a long list of numbers printed on the very top of the door.  I'll try writing them down when I have better lighting and plug them into the intraweb to see if they reveal anything.  There's no saving the existing jamb and just replacing the bottom portion with PVC at this point... I buggered it up too much trying to get the old aluminum flashing off to inspect the wood.

Any experience with / opinions of those "auto height adjusting" (spring-loaded) thresholds?  Found one of those during my research, too.  There's also plenty of height for a run in that area... I had just moved it out of the way when cleaning out the rot.

Considering PVC/composite brick mould on the outside for it's water-proof properties.  My only concern is whether or not it could support a 2/3 window storm door being screwed to it.  I'm not worried about the brick mould coming off as much as I am the screws from the storm door pulling out from the PVC.  Any input? 

Keep it coming, guys.  This is a big help!

straw (post #207465, reply #8 of 44)

I don't advocate packing glue or grout or sandmix under tile to fill the void-but you sometimes do what you have to do to shorten the scope of a job.

If you succeed in correcting the water intrusion problem and all is well for many yrs., outta sight!


This is how I see the rest of the job.   If you can make that steel have good connections and it provides support for under the sill and you could make it also hold up the edge of the unsupported subfloor just inside the threshold are-have at it.  You might want to paint the steel all sides if you plan on living long enough that it might rust out from crawlspace moisture.

Replace the jamb and thresh as a unit.  Find a jamb fabber for residential doors like ThermaTru or Masonite.  Tell them your door size (slab dimensions) and have them supply you with a Frame Saver jamb and non wood backed adjustible threshold (either assembled or knocked down if you can't get it to your place put together.  Have it prep'd for your door slab lockset/deadbolt layout (or plan on doing that yourself-might be safer to match it up to your hung door.)

Tear out your old unit and install the premade pan or one that you fab with a vicor type flexible flashing.  Either way, run more flexible flashing as a counter flashing, above the pan a foot.  Continue with flashing up the side of the opening and behind the siding then install a head flashing, lapping over the side flashing and tucked up behind the siding.  This step is often tough, but to not continue your water stop process around the door at the exterior is to rely solely on caulking later on.  Most often done, not always successful.

The reason it's so hard?  Look at the order of work on building the house.  Frame, sheet, housewrap, doors/windows (weather proof install), siding. 



The drop auto door sweep, complicated and with moving parts, hard to get the perfect seal, anywhere but the bottom.  Not at either end.

I've hung full/half/semi full glass storms off of PVC solid stock and their brickmold.  Have not had a problem yet.

The biggest concern would be the closer connection-your jambs will be wood above a foot from the thresh so you will most likely be screwing into wood.

PVC BM-preassemble the 3 sides and glue them together with PVC cement.  Clamp and let dry or screw them together (they've got some nice composite trim screws-GRK company.   Others make them as well-colored to match the pvc./ composites.  A small box of those and you'll have enough to install the trim.  It will do fine with stainless nails as well, but good luck finding those.  You'll surely have to predrill b/4 handnailing.

Best of luck.

A Great Place for Information, Comraderie, and a Sucker Punch.

Remodeling Contractor just outside the Glass City.


I'd give a thought to cutting (post #207465, reply #4 of 44)

I'd give a thought to cutting away the bottom six inches or so of the jambs and replacing with PVC.  Not sure exactly how you'd join the pieces but I'm sure you could work something out.

Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

Dan (post #207465, reply #5 of 44)

I've done that, more than once.

Believe me-the cost of the new jamb with all the parts working together?   The best way to go.

And a time saver in the long run.


If the casings were period pcs both sides, then maybe I'd do it again.

A Great Place for Information, Comraderie, and a Sucker Punch.

Remodeling Contractor just outside the Glass City.


Yeah, I've done the (post #207465, reply #6 of 44)

Yeah, I've done the equivalent, though with new wood rather than plastic, and it does chew up a lot of time.  But as a HO who (occasionally) finds the work theraputic, the time is not a major issue, and it's really satisfying when it all fits together nicely at the end.

Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

Is there a "standard" place (post #207465, reply #9 of 44)

Is there a "standard" place to find some kind of maker's mark on a door?  All I've found so far is a very long series of blury numbers printed on the top of the door; but can't find any link between that and who the mfg is.  I didn't realize the mfg could just supply an all new jamb/threshold assembly with the composite lowers that I'm wanting; but that does seem like the best solution now that I know it's a possibility.

The most common place for (post #207465, reply #10 of 44)

The most common place for some sort of formal badge/nameplate is the hinge edge.  This is where the rating plates for fire-rated doors are, eg.

Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

straw (post #207465, reply #11 of 44)

Here's the chain of command:

Door slab manufacturer.

Prep and assembly people.  They fab the frames to the door slabs-usually won't sell to the public-but have been known to do so.

The lumberyard that sells it.


Working from the bottom, you can get parts, the whole shebang or anything in between.


While the big box will want to sell you the door unit-they might even get you what you need.



Measure the slab -there shouldn't be a bevel on these.  Not having seen it-I assume it's metal clad with a wood strike edge, top and hinge edge.

Make it exact-go to your lumberyard and ask them to match it up with a manufacturers slab.

Masonite took over stanley-to my knowledge, the older stanley slabs are the same as now for frame size.

ThermaTru-another that's been around a long time-they should match up with their older doors.




Get the number of the fabber and see if they will fab the frame to your door.


In my area, I wouldn't have as much problem.  But I've been here dealing with these folks for a long long time.  They cringe when I tell them I've got something unusual I need to take care of.  But they take care of it.

You're good at picture posting-take a shot of the door, the hinges, the end with the sweep, the latch edge and the latch catch itself (ThermaTru had / has  a goofy sliding backer plate catch (that worked for [JOBSITE WORD]) and that might tell us something.


A Great Place for Information, Comraderie, and a Sucker Punch.

Remodeling Contractor just outside the Glass City.


Hinges say Therma-Tru; so (post #207465, reply #12 of 44)

Hinges say Therma-Tru; so we'll go with that  The door has been painted; but I think the stamp on the hinge side says E04098.

Size is 32x80x1 11/16

When I did the dealer locator on Therma-Tru's website; the place where the siding for the house came from was listed... so I'm guessing the builder doing the addition for the previous owner might have sourced the doors there, too.  I'll start there and see where it gets me.  Thanks again for all of your help!

Straw (post #207465, reply #13 of 44)

Where are you located?

Friday fast approaches and you're buying.


Best of luck in this-hope it works out for you!

A Great Place for Information, Comraderie, and a Sucker Punch.

Remodeling Contractor just outside the Glass City.


Got the jamb/threshold (post #207465, reply #14 of 44)

Got the jamb/threshold assembly on order.  He said probably in next Friday; but may be mid-week the week after.  Fine by me... I have plenty yet to do before I'm ready to swap out the door.  Opted to not have the brick mould installed because I may have to finagle that part of it a bit to get the width I need without messing with the siding. 

You'll be pleased to know I did order it through a local hardware place (VonTobel's) instead of the big box store that was also a Therma-True dealer

Outta sight! (post #207465, reply #15 of 44)

I hope this works well.

You took your slab dimensions to the order?

Pay special attention to your water detailing in that opening.  It might mean popping some siding nails-what type of siding? 

You need to either buy a pan or form one with flexible flashing.  Besides this, you should do a full wrap around the opening from the bottom up and somehow, work it behind the edge of siding and above the house wrap (if at all possible).  Leave a place for the water to get out of if it should work it's way behind.-Channeling of water is way more effective in the long run than trying to caulk the [JOBSITE WORD] outta it.

There are many detail drawings here up top at I would guess, as well at from most door/window manufacturers.

Remember, this not so old door jamb/floor rotted because of poor detailing more than likely........................ or perhaps a real difficult location that defies proper detailing.


A Great Place for Information, Comraderie, and a Sucker Punch.

Remodeling Contractor just outside the Glass City.


I'll probably just buy a roll (post #207465, reply #16 of 44)

I'll probably just buy a roll of the peel and stick flashing to use.  I'll be buidling a garage this year that will have 4 windows, a side entry door, and 3 10x12 garage doors; so I'll have enough stuff to flash on that project to justify the investment.  I did take the door slab measurements with me.  Once the guy knew it was a 2/8 , 6/8 Therma-Tru door for a 2x6 wall, he didn't seem to think the exact measurements were that critical.  Don't worry, I'll be flashing the heck out of everything; and am also considering having an aluminum drip edge bent up to go above the door and another for above the 8' wide window beside the door.

By the way, any particular (post #207465, reply #17 of 44)

By the way, any particular brand of peel and stick flashing you feel is "best"?  Is there any difference between that stuff and the self-adhesive mastic I already have?  The particular stuff I have  is rubber-based instead of asphalt-based; so it doesn't off gas with a bunch of odor for months after it's installed:

Straw (post #207465, reply #18 of 44)

I'm not sure of it's application-might work.

I've used and like Fortifiber


and  products from Protecto (protecto wrap).


They both have (I beieve) non-asphalt based products.  The ones I like can form around you can go around and up as well in the corners with the same flashing-you don't have to keep building it up.


On the interior, I like to turn up the back so it keeps water possibly from coming into the floor finish (what a pan would do). 

A Great Place for Information, Comraderie, and a Sucker Punch.

Remodeling Contractor just outside the Glass City.


Looks like the Fortiflash (post #207465, reply #19 of 44)

Looks like the Fortiflash Butyl would be similar to the sound-deadening stuff I have (which is also butyl-based).  Probably better for this application, though, just due to the shape.  The butyl product I have already is in 2'x2' sheets... maybe okay for forming the sill pan; but not so convenient for flashing around the door and window.  I'm sure minimizing seams is preferred from a potential water penetration standpoint.  I'll look into hunting down some of the Fortiflash Butyl.  They also had great instructional videos for install on their website.  Thanks for the lead!

Would you recommend the 6" wide roll? (comes in 6", 9", or 12" from what I've found).

straw (post #207465, reply #20 of 44)

I regularly have both 6 and 9 in the shop, and most often somebodies brand that's about 4".  I take all to the job and use what works.  Flashing with good stick takes care of most seams as the tenacious stuff will probably never come apart.

I don't know if time is an enemy, but there were a couple brands (and without a name on the release paper (or the product itself), I cannot give the maker) that gave up the stick.  Not good.

Tyvek had a nice product, but when it came out it was one of the most expensive.  Some of the other house wrap makers have flex. flashing as well.

See what's in your neighborhood.



So, where were you last night (it was Friday you know), the Village Idiot was packed- so surely didn't have to drink alone.  It was your turn to buy however.

A Great Place for Information, Comraderie, and a Sucker Punch.

Remodeling Contractor just outside the Glass City.


These are what are in my (post #207465, reply #21 of 44)

These are what are in my neighborhood:

"Peel and Seal" brand

"Vycor" brand


Not sure what the "local" hardware store where I ordered the jamb through carries (it's in the city where I work ~30 miles away); but I can check when I go to pick up the jamb.  Not able to locate the Fortifiber locally.  I don't mind buying it online if it's a lot better than the stuff listed above; but the shipping from the online places I've found is as much as the product (ends up being $50 for a 6" wide x75' roll). 

I am considering using this for the drip edge edge above the door and window:

I assume I'd roll up the house wrap to expose the sheeting, then put on the peel and stick flashing, drip edge on top of that, then house wrap rolled back down over the whole thing with Tyvec tape to adhere it to the drip edge?  That is what I'm gathering from the instructional videos I saw; but want to confirm... don't want to have to deal with this again!  Probably just wait until it warms up a bit to do all of this to be honest.  I know it's going to end up taking a solid weekend or two for me to remove the siding from around the door/window from the bottom to 1' or so above them, cut out and replace any more rotten stuff I find along the way, and then rebuild everything, flash, and trim out, re-install siding, etc.  The two floor joists I can see right now (ones in the picture) are a bit squishy from the outer edge to ~8" in.  Wondering if I should just be preemptive and take off the ledger board to investigate the adjacent floor joists.  Might have to pound some 4' lengths of PT 2x10's beside each existing joist and through bolt them to the originals to strengthen things up a bit.  The wall in that area is settling enough that the drywall joint in the upper corner of that door has a 10" tall crack running up with an 1/8" gap.  It's progressed from a wrinkled spot in the drywall paper to it's current status within the last 6 months... and that frightens me a bit. 


[edit] as for the drinks... trying to save up for the 26x36 garage I'm building onto the house this year... no funds for those luxuries at the moment

Straw (post #207465, reply #22 of 44)

Check out this video-it's for a french, but the system is the same.

Pay attention to how he lays the flex.flashing over then up the backside of the jamb-he's got a flange on this door, but you won't.  So, it's important that you carry some of the flashing onto that jamb.

A Great Place for Information, Comraderie, and a Sucker Punch.

Remodeling Contractor just outside the Glass City.


Door jamb is home (going to (post #207465, reply #23 of 44)

Door jamb is home (going to be awhile before I actually install it); but I had some questions about the flashing.


They only had the Protecto flashing in 4"; so I grabbed the 6" they had in the Typar brand:


The Protecto butyl hybrid flashing has the following statements on it:

"Use only with non-solvent based sealants."

"Should not be used in direct contact with flexible (plasticized) PVC-based membranes and products: ie. flexible J channel."



1. So... what sealant should I be buying to use with this stuff?

2. My siding is vinyl.  I'm not sure if it's "plasticized" or not; but it seemed pretty flexible when installing it.  Is that going to be an issue with the Protecto stuff based on the above statements?  I intend to use Azek PVC trim on the outside; but I'm not as concerned there as it's not flexible at all.

3. I opted to not have the brick mould put on the new jamb from the factory.  The way the people finishing the addition for the previous owner did things, I'm going to have to do a custom 4.25" wide "brick mould" to have the inside distance correct for the storm door while still having the outside end where it needs to for the existing siding.  My intention is to get some 5/4 x 6" wide Azek PVC trim to rip down to 4.25" and use.  Should I attach it to the jamb before or after install?  Any reason galvinized or stainless exterior deck screws couldn't be used for this, then the holes covered with white caulk?   

When I replaced our front (post #207465, reply #24 of 44)

When I replaced our front door I removed the brick mold, tacked  on 4 pieces of scrap in place of the brick mold to position the jamb flush with the frame, and aligned/fastened the jamb.  Then went back and measured/ripped the brick mold to fit the existing siding (pre-priming the cut edges before install).  This worked out well.

Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

Straw (post #207465, reply #25 of 44)

I'll have to take a look tomorrow, when back in town.

A Great Place for Information, Comraderie, and a Sucker Punch.

Remodeling Contractor just outside the Glass City.


Straw (post #207465, reply #26 of 44)

to my knowledge-solvent based caulk with butyl flex flashing-Don't use black roof goop in a tube.  You don't use it with rubber roofing.   Caulks that clean up with thinner-Urethane for example-are alright.

OSI Quad-many colors often matched to various vinyl siding colors (named by manufacturer and color) are listed on the tube.  This is not that easy to work with-but somewhat easier than using Urethane caulk.

Any siding touching the flashing will be in no real contact with the guts of that flashing-most will have a "cover" or top coating on them. I've had no problem.  Read further on these butyl flashings-if you have the flex flashing used to wrap windows-it's what it's made for.

Good idea to not put the trim on the jamb until after the install.  You are then able to detail both the flashing up to and onto the side of the jamb, sealing it all around the opening.  Then install your trim.  I often use trim screws (exterior grade only) from GRK and / or some of the other brands-Fastenmaster and Griprite are a couple. I'd fill the holes with reg. exterior filler or even epoxy b/4 I'd use caulk.  Often it's the "finish" of filler that clashes with the look of the PVC trim finish.  It looks different-not as easy to blend  when sanded like fills and wood.  So-plan your screwing schedule to be decent looking when done.  Don't just blast the screws in anywhere.  Keep the same pattern.


use nails.

The ones you put through into the jamb itself will be covered by the storm mounting.


A Great Place for Information, Comraderie, and a Sucker Punch.

Remodeling Contractor just outside the Glass City.


Thanks to both of you for the (post #207465, reply #27 of 44)

Thanks to both of you for the help.  I have plenty of scrap boards laying around the garage; so I'll use those to place the jamb, then remove them and do the flashing, and end with the Azek trim and sealant.  Polyurethane sealant is one of the recommended ones listed on the instructions for the door jamb as well; so I'll likely use that.  Luckily all of the existing exterior trim is white; so I don't have to worry about painting the trim or color matching the sealant with anything "custom".

straw (post #207465, reply #28 of 44)

Titebond makes some nice sealants.  Much easier to work with than Urethane.  Might check them out.

It dries in the spout quickly, but their spout is removable, so you can pull out the "plug" if too hardened.

A Great Place for Information, Comraderie, and a Sucker Punch.

Remodeling Contractor just outside the Glass City.


Took the catch side of the (post #207465, reply #31 of 44)

Took the catch side of the jamb off today:


I know one would typically put the new jamb in from the outside, using the brick mould or scrap wood screwed to the outside of the jamb to line it up flush with the exterior sheeting.   My question is, can I secure some scrap wood to the side of the existing exterior trim (see outlined red area in below picture) , then install the new jamb from the inside?  This should still place it flush with the exterior sheeting; and would allow me to keep up my high-tech plastic "storm door" until I'm ready to do the exterior flashing and trim work in case I run into a snag and can't get it all done in one day.

straw- (post #207465, reply #29 of 44)

no pictures.

A Great Place for Information, Comraderie, and a Sucker Punch.

Remodeling Contractor just outside the Glass City.