Replacing exterior doors with rotted sills

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Jun 5, 2014
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I've mentioned this before in other threads, but I need some help with installing a replacement exterior door.

The house is wood with vinyl siding put on years after the door was installed so I don't know the situation with any flashing or house wrap (although I vaguely recall that when the new siding was put on it was some sort of pink stuff).

The previous steel door had been stolen by the tenants (who claimed it was broken) and it was replaced with a very crappy wood door. Because the parquet flooring had been destroyed, the level of the floor was lowered and thus they cut the frame short and lowered the door (so low that it scrapes the substrate/floor when it swings in). It tore the linoleum up and it's now just plywood or something there.

There were huge gaps so we filled them with expanding foam (which I think was a mistake bc it may have warped something so the door won't stay shut properly anymore and I have to prop something against it).

I know I will need to cut out the top filler part when the new door is put in. We got this prehung door on sale. So it will be about a 36x80 door. It came with narrow trim for the exterior (current exterior trim is crappy 4" wide planks with peeling paint). The jamb depth is 4-9/16".

I think fixing the top part and getting the door plumb is not difficult to figure out-- but, I'm trying to figure out what to do about the sill and floor part. The exterior sill is in bad shape and there is some sort of wood between the sill and the threshold that is rotted. I'm trying to figure out the best way to fix it.

I want to raise the door back up to allow for higher finished floor should we ever choose to get vinyl plank or thicker flooring material.

So, I need advice on what to do about the rotted wood, installation, and moisture prevention.

I am leaning toward getting some sort of PVC material so it won't rot since I live in a very humid climate and even treated lumber rots here.

I saw a few Suresill sloped PVC door sill "complete packs" and assume I need 4-9/16"D sill pan pack(end caps, sill, and pvc glue & applicator). I will probably still need some flashing tape or something. There is also a head flashing kit but it is 1-3/8"D.

Additionally, I have a sliding door with rotted wood (almost identical-- if not worse-- to the rotting on the swinging door). So I am wondering about getting a Suresill specifically for vinyl sliding doors (if we ever get a vinyl sliding door-- I will need to measure the jamb depth, which might be tricky because the track got bent and the door is difficult to open for measuring purposes). The sliding door ones only come in 3-1/4"D but replacement sliding doors are over 4" thick.

My questions are:
1. Is it worth getting the Suresill sill pan and having to notch the pre-installed exterior trim that came with the door? (It's around $23 for the pack)
2. Is it worth getting the header pack?
3. How do I deal with/replace the rotted pieces under the existing threshold?
4. If it is not worth it to get the packs, what should I get instead?
5. What is the piece of wood under the threshold called? (It looks too thick to be subfloor).
6. Since the moisture is getting in (despite the door being under eaves that extend out over 1'), should I do this asap or wait until I'm replacing the entire subfloor in the area?
7. Any suggestions/advice?
BONUS: Could anyone please recommend a good lockset with deadbolt that can easily be rekeyed to use existing keys? (Mother would like it in polished brass).
Here are some pictures of what I'm dealing with. Let me know if anyone needs more pictures.

Rotted sill & whatever that piece is under the threshold along with peeling rotting door (cinderblocks will hopefully be replaced with real steps eventually). Could that be just the edge of the subfloor and substrate that has bloated and separated from moisture damage?

Interior view (the edge under the threshold has been rotting and sinking)

Closeups of the exterior rot/damage


* I have not yet picked a replacement sliding door (I believe the current one is 72x80) so I am not ready to replace it yet, but it has the same type of damage to the sill-- I will have to get pictures later.
* I am considering building a small platform just outside the door so there is more space when stepping out, but I will need to figure out how to do that and make sure it will not rot, warp, or break. I will need to figure out just how large to make it. Maybe something like this only not as deep (and somehow allowing access to the water faucet just just outside on the left).
Last question first. Newer key sets have the ability for you to change the keys yourself so with the help of a good apron they might find you one that uses the same key blank you have and then you could re key it to match your other doors.
Your old door has flat wood trim around it and the new door should have brick mold attached, After you have installed the door, remove the brick mold and replace it with new wood that fits the gap.
I have not seen a sill pan up close but yeas you want something we use the blueskin just like the windows. Water can and will get behind the frame of windows and doors and need a way out so we start at the floor with blueskin and then protect the framing with house wrap or something so water runs down and not into the wood.

On the inside can you measure the framing of the house and make sure the hole is 38" wide and from the subfloor where the cat is standing to the top framing is 82"

Jobs like this often goes sideways when a home owner gets into it so make sure you have enough plywood to cover the hole if you don't get it done in one day.
The head flashing looks great but siding will have to be removed for that so let's get more info first or buy it and a length of Z flashing so a decision can be made at the time.
Z flashing should be able to slide in with out removing siding and adjusting the top trim size. The picture does not show the ends turned up so wind doesn't drive water sideways.

Z flashing.jpg
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I just typed up a long message but somehow it got eaten... 2nd attempt...

The sill pan kit I was looking at is a PVC bottom frame that sits under the threshold. It is supposed to be cut a little shy of the width of the rough opening so the end caps can be secured with PVC glue. It would go over existing house wrap or flashing-- so I could use something similar to that blue tape stuff you mentioned underneath.

The instructions recommend peeling back the siding just around the edges a bit-- although I wonder if that will be fully necessary if I just take off the old 4" trim. I plan to replace the old trim with something that won't rot- painted PVC or something. I need to measure the trim that came with the new door and see how much of a gap there is between the vinyl siding and the new trim. I think the new stuff is only about 3" or so, but I'll have to take a look when I go down there.

The exterior top of the door has the same flat wood trim as the sides. I managed to find a picture I forgot that I'd taken.

Bottom of the door doesn't look good

Top from the inside

I'll just link additional pics since I'm only allowed 4 per post. I wanted to get more exterior shots today but it was raining hard. We did manage to find a brief window of light rain to get the doors in to the barn.

Fuzzy wide shot of the door from interior (note how crooked it is).

Exterior shot of top of jamb with door closed.

Interior shot of the knob-- more sunlight coming in.

And here you can see the weather stripping from the interior with door open.

I don't know if the new door has weather stripping since we weren't able to open the ones they had at the store.

NOTE TO SELF: Z Flashing.

I think we've figured out what lever/lockset to get. I think we will move the lever from the front door to the back door (since it was just the lever we replaced and the key does not match the one for the deadbolt). We will then replace the deadbolt and lever on the front door with something sturdier. I'm thinking Schlage flair lever with standard trim & a deadbolt. I was told by customer service that if we take the lockset to the key cutting area after purchase, they will rekey it to match an existing key.

The Kwikset had some sort of smart key thing that let you rekey it yourself BUT, the ones we were looking at in the same price range as the Schlage had bad reviews-- finish peeling off, plastic parts, jamming and having to be cut out, breaking off, etc. Schlage has thicker screws and a better design to prevent someone from breaking in. We aren't worried about people breaking in, but longevity is something we want-- and it has a lifetime warranty. If the finish wears off, it is covered under the warranty.

I need to wait for a nice dry that isn't too hot to go out and take a peek under the threshold to see what I'm dealing with and if I should just replace the entire floor at once. I already have several sheets of plywood in my workshop, although I'm wondering if I should get the kind that has grooves to click together that is specifically designed for floors.

The good news is, once Mom found out about the military discount and I showed her pictures, I actually got her excited about renovating and getting things fixed up (plus I told her I will pay for the laundry room/bathroom reno myself). Once she saw how bad the back door looked she realized how important it is to get it fixed. All that moisture and heat keeps coming in. We have a thick curtain between the kitchen and that hallway to keep the heat out.

Would it be better for me to do the painting on the door and trim before installation? It's all primed right now-- and I was thinking of painting some of the pieces that will be hidden once is installed-- just to make sure it is sealed against moisture.

And I'm guessing that if I measure first and make sure I have enough plywood of the right thickness on hand before I start, I could do the floor first and make sure it is more level. I'll just have to hope for dry weather corresponding with clear schedules for my friends. I'm going to help my friend when he fixes up his burned house so he's happy to help me.

I can probably get more info on the flooring forum about the subfloor stuff though.

So, should I wait for the floors for the whole area to be fixed before I mess with the door? Or should I just fix the area where the door will sit first and then fix the rest later?

Is there anything I forgot to address? Sorry this is so scattered. I'm exhausted today.
zannej; I will try to put a set of instruction together for you to follow.

I want to slow it down and get the right information in the right order.

First the measurements I asked for the rough framing measurement from stud to stud on each side of the door.
And from the floor inside to the 2x4 on flat above the door frame.
That sill pan is better than blueskin if there is room for it. We will see when you get the measurements of the opening.
Thanks, Neal. I wish I could remember where I wrote the measurements down. I did measure the studs around before. And I need a better measurement of the framing-- I think it was under 6" but more than 4" (but that was including the exterior trim).

The subfloor and substrate are showing signs of water damage all the way under the house where the shower stall is. It spans over two joists at least. The plan was to tear it all out and replace it with something more durable and moisture resistant.

The damage in the laundry room extends to the top layer of floor as well-- although that could have been from a hose leak while the tenants lived here. The guy who installed the crappy sheet vinyl poured some white powder and added water to it to try to fix the damage, but the stuff broke apart when we moved the washer and dryer. I don't have to mess with the flooring for the part that will be the bathroom just yet. I'd like to get the area closest to the door fixed up and I plan to knock out a wall.

I'm just debating whether or not I should just do the one section first to have it fixed for the door and prevent more moisture from coming in and then do the rest. I will have to tear out the wall before I do more of the work on the floor.

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I just measured-- stud span (not including some large shims) around the door is approximately 39 inches.

When I measured the floor to header it was about 81" on one side and 82" on the other. The header looks like some of the wood has split and the vertical boards on top of it don't go all the way up to the boards above. I *think* that I could probably shim it back up again-- but it explains the big gap above the knob side of the door.

Upon looking at the pictures of the door threshold more closely, I think it looks like two layers of plywood.

I'll wait until daylight (and rain cessation) to measure the jamb depth again.
I just measured-- stud span (not including some large shims) around the door is approximately 39 inches.

When I measured the floor to header it was about 81" on one side and 82" on the other. The header looks like some of the wood has split and the vertical boards on top of it don't go all the way up to the boards above. I *think* that I could probably shim it back up again-- but it explains the big gap above the knob side of the door.

Upon looking at the pictures of the door threshold more closely, I think it looks like two layers of plywood.

I'll wait until daylight (and rain cessation) to measure the jamb depth again.

I think I have figured out why the door sill is lower that the floor.

The original old door was only 78" high, standard when the house was built.

When the door was changed to an 80" they went down instead of up.

There is some changes that can be made before the door is pulled out.

Can you pull the insulation in this area and maybe step on a ladder and get some pictures of detail there of wiring and framing

I didn't have the ladder handy but I got up on a chair.
The insulation was somewhat stuck on the foam, but I found that the electrical runs from the top and probably in to the attic and then to the left because the electrical box is directly next to the door on the left.

I will need to replace that nasty insulation with something better.

I'm not sure if these photos are very good. I might need to get more.

Left side-- cobwebs got in the way. The gap between the 2x4 & the next horizontal piece looked larger from down low.


I apparently forgot to get one of the ride side.

Wiring for the external light-- probably not kosher to have the insulation sitting on it like this with no fire protection.

I was afraid that if I pulled the insulation all the way out that it wouldn't go back in.

Are these good enough or do I need to completely remove the insulation and get wider shots?

I have a friend who has installed doors numerous times so he will be helping me. I have the appropriate cutting tools needed for pulling out the stuff above the header and cutting it more evenly so that I could prop it up more. I'm seriously considering moving the whole header up even more so that the finished floor can be higher (and thus bring the threshold up a bit more). The new door came with a threshold so I will have to examine it to see what kind it is (I think it is vinyl top rather than saddle but am not certain).

I'm thinking of getting this tool (not sure if it would help with this project though).

And I wonder if the door hanger kit would actually help.

Edit: they have instructions on how to do exterior door installation.

And this for shims if the hanger kit doesn't work for exterior doors.
(some of this is to remind myself what stuff to get)

Also, I used a level and the floor slopes downward to the left (while facing the door from the inside). I think it could be the whole area slanting- perhaps from a bad build or from settling.
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The friend you have to help you, does he have a sawzall type saw?

The wire coming down from the attic, can you get a good look at that and see if it is in the middle of the 2x4 or closer to the inside or the out side?

Are the 2x4 actually 2x4 or are they 1 1/2 x 3 1/2?
I'm guessing they are not fully 2x4. I know they make them slightly smaller than the listed measurements. I can't check right now because I borked my ankle. My brother's dog tripped me and while I was trying to catch myself I managed to turn my foot so I stepped down on the side of it instead of the bottom. Got it wrapped with an ice pack and elevated.

I think I have a sawzall. If not, I think my friend does.

When I'm back on my feet again I'll have a look at the wire to see if I can trace it's path.

I'm going to need new insulation-- thinking of getting a combination of Roxul rock wool (fire and moisture resistant) and Reflectix radiant barrier. I'd put the Roxul against the exterior and have the Reflectix on the interior-- hopefully it would help hold the Roxul in place-- although I might just tack some nails in so they stick out enough to hold the Roxul in place. Radiant barrier on top of it might be overkill. But, maybe it will be worth it if it keeps the area cool in summer and warm in winter.

Someone suggested a storm door would help, but I don't know what to get that wouldn't block the cat door. They have some with built-in pet doors but it would conflict with the existing pet door. So, I'm thinking maybe a screen door with a cutout-- letting them through to the pet door. I saw a screen door that is covered on the lower part but I could probably cut a hole for the pets. There was another screen door that has a pet door on it although it is more expensive than the back door we bought and has some negative reviews about the sturdiness.
There was also a storm door with pet door but it was a bit too high in price.

I know I'm getting ahead of things. I know I first need to deal with the header-- figuring out how to move the electrical box up without screwing with the remains of the fixture on the outside.

Does it make much of a difference if the 2x4s are really like 1.75 x 3.75 instead? I could have sworn they do 1/4" smaller rather than half but I could be wrong. And it was done a long time ago so materials may have changed.

I need to figure out just how much higher to move it and thus how high the threshold will be compared to the subfloor. I'm seriously considering just having sheet vinyl for the finished floor and then using some sort of ramp to bridge the height gap from the threshold.
Sorry about the foot. Hope you never broke anything.

The electrical box in the picture is for an inside light, the one facing outside must be just above that.

I am hoping we can make the change without touching the siding or light out side.

Up here, we always put the header at the top of the wall, so adjusting height for a door is much easier.

So my plan

Remove about 8" of the top of the two 2x4s above the header.
Make a new header out of full length 2x6 with plywood spacer between to allow wire to fit between them Hopefully
Install that in the top of the wall and add tight blocks between new and old headers.

After the door is removed cut the old header straight up beside the studs under it on both sides and remove it.

Replace it with a 2x4 .then cut the extra outside sheeting that would be below the new 2x4

So if the old header is 3 1/2" the new sill would be 2" higher.
Zannej: the door you picked appears to be steel clad. It has only one hole bored so you will either have to bore another hole for the deadbolt or skip it. Also, your new door has no pet entrance...also hard to cut in a steel door. Think this through very carefully before you do anything, or you will be without a door for days.
You can probably download instructions from either the Lowes site or the Masonite site. Don't think of this as a patch job or you will end up with that as a result. Make sure the rough opening is solid and to spec.
Neal, the box may be for an interior light, but it was used for an exterior light. The builders did a lot of things wrong-- like that toilet in the 23" alcove. Do you have any sketches of what you're talking about? I'm trying to visualize it but my brain doesn't want to work. Maybe it's because I'm tired.

Slownsteady, the new lockset will be for the front door (which is wood and already has holes for things). We are going to take just the lever from the front door and move it to the back door and then replace the front lockset so the keys match. Currently the deadbolt for the front door does not match the lever in terms of keying. We had a cheap knob that came with the deadbolt and the knob broke off so I replaced it with a lever.

I'm going to look in to the best methods for cutting through the steel and I will make sure to use the template for the pet door and doublecheck before any cutting starts. When I asked at the store if the door could be cut for a pet door they said "Yes".

I plan to put the pet door on before installing the door. That way I can cut the hole, prime it, paint the whole setup and then put in the pet door (with some door & window silicone around and behind it). Then I'll fix the header & such as per Neal's instructions & install the door. Might need to do more about the floor first though.
door & window caulk is not silicone

cut the cat door hole with a jig saw with a metal blade after drilling a hole.

The light detail is what i wanted to see with out insulation.

Did you understand how to replace the header.
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door & window caulk is not silicone

cut the cat door hole with a jig saw with a metal blade after drilling a hole.

The light detail is what i wanted to see with out insulation.

Did you understand how to replace the header.

Yeah. I've got a jig saw. Just need to get the right blade and the right drill bits for the metal.

My ankle is feeling better so I can walk on it. It's doing much better than the time I broke / dislocated my other ankle. It took me 2 years to be able to walk without a limp on that one. I still can't jump or do anything too strenuous on that ankle. And this one has healed much faster, but I'm sick as hell with some kind of stomach bug. Can't even drink water without it hurting my stomach. It was kind of funny because I had the chills last night and I muttered something about being cold and my cat (who was sitting on a shelf near the door) reached up and pulled down the switch to turn off the ceiling fan. Pretty sure it was a coincidence though. LOL. Right now I'm waiting for my bro to get up so I can give him money and send him to the store to get some medicine for me.

But, back on topic, when I'm feeling better I'll try to get better pics of that light with the insulation moved out of the way. I think I already know what insulation to put in it's place, I just have to order it.

I think I understood what you were saying about the header but am not certain. Are there any youtube videos you've found that are good examples?
OK Well this guy didn't need a header and didn't need the 2 2x4 but you would have to go up to the to[ of the wall with blocks below from the old header to the new.

With the wire there you will not be able to pre build it. you will have to put in the 2 pieces separately with a space between to give room for the wire.
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I installed one of those cat doors that have a collar tag to open, they have a kit that reaches thru the exterior wall. I put it under a window, I thought that was better than cutting into a door.
I installed one of those cat doors that have a collar tag to open, they have a kit that reaches thru the exterior wall. I put it under a window, I thought that was better than cutting into a door.
We just don't have any places on the walls where we could put a cat door. The exterior wall surface is pretty much covered with cabinets or is in rooms the cats aren't supposed to be in.

I saw this video on making a header. Is this what you were talking about?
How thick is that plywood?

And then there was talk of an "engineered" header
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