Does anyone know what is going on here?

[solent_sailor]

Hi, hoping someone can help. I've noticed that the corner of our front door sill has recently become significantly raised. Looking under it it looks like a combination of foam and some strange looking metal plate. The metal is only under the corner and appears to perhaps have delaminated (if that's possible for metal). It's definitely not right and I'm not sure what to do about it or who would be the best trade to call.

Any advice appreciated.

 

[jamespipe]

It looks like a fix for supporting that corner.

 

[JoeD]

Looks like spray foam. If the wrong stuff was used the expansion can lift things.

 

[solent_sailor]

Looks like spray foam. If the wrong stuff was used the expansion can lift things.

Thanks, it's been ok for years but I suspect you're right and it's finally become saturated? Any tips on what I can do?

 

[JoeD]

If it has been fine for years then it is not the spray foam. It could be the metal rusting and expanding.
I don't know how difficult it would be, but I would try and remove the flashing and investigate what is going on.

 

[solent_sailor]

It looks like a fix for supporting that corner.

Thanks, it's something that a previous resident or the original b

If it has been fine for years then it is not the spray foam. It could be the metal rusting and expanding.
I don't know how difficult it would be, but I would try and remove the flashing and investigate what is going on.

Thank you

 

[BvilleBound]

Sorry but I have to disagree with JoeD. Canned spay foam, e.g. Dow Great Stuff, is “single component” foam that cures by pulling moisture from the air. If the person who installed this sill placed the sill immediately on top of the foam - or spayed a bunch under it later - the foam would not have cured completely. When moisture seeped in later, e.g. along that rusting piece of metal, voila! More expansion.

Joe suggested the right solution: you need to

1. Remove the sill, scrape off the foam and remove the metal piece, then create a new, solid surface for the sill to rest on. Clean the old surface thoroughly.
2. If you need to build up the surface, the best option will be a thin layer of concrete or mortar. The new sill will need to slope away slightly from the door.
3. If the height is >1”, start by installing a small fence to contain the cement, with 1x pine trim. The top edge of the pine fence should have the slope, so that you can simply pull a board across the top of the new cement to flatten it. The fence needs to be stable and secure. Then apply a concrete ‘bonding agent’ (available from Home Depot) to the original surface, following the directions on the bottle. Then mix and install a thin layer of cement or mortar. When the fence is full, let the concrete/mortar sit and settle for a fe minutes, then draw a piece of the pine trim over the top, following the slope of the pine fence.
4. If the height is less than 1”, you can build up a new sill support with flat pieces of tile and mortar. Apply cement bonding agent to the old surface first, Apply some mortar then tile, ‘buttering’ the bottom of each piece of tile with mortar. You will need to carefully check the height and slope with a level, and gently tap tiles with a rubber mallet or piece of wood to align them.

I hope this is helpful.

 

[solent_sailor]

Sorry but I have to disagree with JoeD. Canned spay foam, e.g. Dow Great Stuff, is “single component” foam that cures by pulling moisture from the air. If the person who installed this sill placed the sill immediately on top of the foam - or spayed a bunch under it later - the foam would not have cured completely. When moisture seeped in later, e.g. along that rusting piece of metal, voila! More expansion.

Joe suggested the right solution: you need to

1. Remove the sill, scrape off the foam and remove the metal piece, then create a new, solid surface for the sill to rest on. Clean the old surface thoroughly.
2. If you need to build up the surface, the best option will be a thin layer of concrete or mortar. The new sill will need to slope away slightly from the door.
3. If the height is >1”, start by installing a small fence to contain the cement, with 1x pine trim. The top edge of the pine fence should have the slope, so that you can simply pull a board across the top of the new cement to flatten it. The fence needs to be stable and secure. Then apply a concrete ‘bonding agent’ (available from Home Depot) to the original surface, following the directions on the bottle. Then mix and install a thin layer of cement or mortar. When the fence is full, let the concrete/mortar sit and settle for a fe minutes, then draw a piece of the pine trim over the top, following the slope of the pine fence.
4. If the height is less than 1”, you can build up a new sill support with flat pieces of tile and mortar. Apply cement bonding agent to the old surface first, Apply some mortar then tile, ‘buttering’ the bottom of each piece of tile with mortar. You will need to carefully check the height and slope with a level, and gently tap tiles with a rubber mallet or piece of wood to align them.

I hope this is helpful.

Thank you very much, that's an incredibly helpful answer! I've asked the original installers to come back and have a look. I'll try to make sure it's installed properly this time.