Hearth extension has separated from the fireplace

[Willkellysims]

Hello!
Long story short we are new homeowners who got a fast one pulled over on us regarding our fireplace. It is not safe to use for several reasons. Eventually we will have an insert put in and that's ok with us for now, but our situation currently is (I believe it's called) the hearth extension has separated from the fireplace. The mortar or whatever the previous owner used has literally turned to sand and started crumbling leaving a large gap. The hearth extension sits on the subfloor. (We found out it was not properly supported underneath and installed a few of those column Jack things under the floor in our basement for more support) it appears as though this hearth is just one giant separate piece. We/I know nothing about this kind of stuff so please forgive my ignorance and lack of appropriate terminology... We are hoping we can remove this piece and continue with updated flooring ECT.... And need help figuring out if we can remove it, or is this a structural piece that may compromise the fireplace structure, or should we just do a slow lift with jacks and refill the gap?? Thanks for your help. I will try to post pics as well.

 

[SKIN052]

Wow! Structural problem for sure. Good news is that it seems completely separate from the main Hearth and removing it will have no effect on the functionality of the fireplace. Depending on what you put in for a insert you will have to be concerned with clearances toward the front. Pics from underneath where you put the jacks would be interesting to see.

 

[Willkellysims]

Thanks for taking a look and helping. You are correct in using the word interesting for the underneath where the jacks are. I will have my husband get pics that are actually visible here in a bit, the subfloor was poorly supported and constructed. The fireplace is part of the house that is an addition the previous owner built himself in 1975. I hope removing it will not open Pandora's box, but if nothing else it will help take some unnecessary weight off my floor. Thanks again for your help.

Wow! Structural problem for sure. Good news is that it seems completely separate from the main Hearth and removing it will have no effect on the functionality of the fireplace. Depending on what you put in for a insert you will have to be concerned with clearances toward the front. Pics from underneath where you put the jacks would be interesting to see.

 

[TheRambler]

Pics from underneath where you placed the supports would give the big picture. Judging from the pics already posted it really doesn't seem that bad. Not built exacty perfect, but its an easy fix. Essentially it appears as if the mortar joint is just too big. Easy fix would be to clean out the joint and then put in some wire mesh or some short rebar pieces and refill with the proper mortar. It does appear to be a completely separate piece, and they are not connected properly which is why overtime this occurred. Chances are with the supports you added, it has settled as much as it will and refilling the joint will make it 100% functional again and it probably wont happen again. This would be probably less than 40 bucks to fix.

 

[TheRambler]

Forgot to add that it being directly on the subfloor is not a issue. It could also be removed if you desired, and you could just build a new hearth. Though that would be much more expensive.

 

[Willkellysims]

Forgot to add that it being directly on the subfloor is not a issue. It could also be removed if you desired, and you could just build a new hearth. Though that would be much more expensive.

Thank you!! Your suggestion of clearing out the old and refilling with the right mortar and rebar/mesh sounds exactly like the perfect plan of attack for us. We are new DIY'ers and really prefer not to bite off more than we can chew. (Has happened a lot this first year owning a home .. If we remove the piece entirely, we would be shooting ourselves in the foot I think. Husband is taking pictures of underneath now so I will post them shortly. With the gap being so large, should we attempt to tighten up that gap before remortering or is that where the rebar and mesh help as far as the gap is concerned and the supports underneath would also help keep it stabilized?

 

[TheRambler]

Supports underneath will keep it from further separating, If that is what was happening at all. The purpose of the wire mesh will be to hold the mortar together and give it more structure and strength. aka keep it from cracking apart. Normally you don't have to do that, but in this case the gap is much larger than a normal mortar joint.

 

[TheRambler]

It looks like it only pulled away a very tiny amount though the picture is rather dark, and that it was really just the mortar breaking away overtime due to no support that has caused the gap. A masonry chisel small enough to fit in the space and a hammer are about all the tools you should need. Clean it out as deep as possible with the chisel, vacuum it out, etch the brick on the insides of the gap with muratic acid (may not be needed, but recommended), cut a piece of wire mesh to fit and then refill.

 

[jatoxico]

Is this an exterior (on an outside wall) chimney or interior? Hard to tell from the pics but it looks like the fireplace was repointed (new mortar) in some spots. It makes me wonder if the whole thing is moving.

 

[Willkellysims]

Supports underneath will keep it from further separating, If that is what was happening at all. The purpose of the wire mesh will be to hold the mortar together and give it more structure and strength. aka keep it from cracking apart. Normally you don't have to do that, but in this case the gap is much larger than a normal mortar joint.

That answers my question exactly. Thanks again it makes perfect sense. We believe the reason for it separating was due to the poorly supported subfloor and age of mortar I am sure contributed as well.

 

[TheRambler]

Is this an exterior (on an outside wall) chimney or interior? Hard to tell from the pics but it looks like the fireplace was repointed (new mortar) in some spots. It makes me wonder if the whole thing is moving.

Good point. repointing haven taken place isn't necessarily because of movement, though it could be. Do any of the bricks have vertical cracking, or any of the mortar joints cracked? If there are a number of bricks with cracks it is possible the entire chimney footing has shifted some.

 

[Willkellysims]

Is this an exterior (on an outside wall) chimney or interior? Hard to tell from the pics but it looks like the fireplace was repointed (new mortar) in some spots. It makes me wonder if the whole thing is moving.

It is an exterior chimney. We have inspected outside around the house where the chimney meets for any cracks or separation from the house and do not see any... with that being said, we can only assume we know what we are looking for.

 

[jatoxico]

It is an exterior chimney. We have inspected outside around the house where the chimney meets for any cracks or separation from the house and do not see any... with that being said, we can only assume we know what we are looking for.

Well that it's an exterior chimney is probably a good thing in this case. If the fireplace is sitting on a good base of support using concrete then should be OK. If you find the base is under built, you would be able to beef it up if it's not out of hand.

You said it's unsafe to burn in, why is that?

 

[TheRambler]

There are only really 3 or 4 things that can be happening. Chimneys are built on a footing that is independent of the house foundation. 1)Chimney footing shifted/settled, which caused the chimney to move away from the hearth piece. 2) The chimney has leaned away or sideways from the house(usually due to poor constructon like bricks not laid all on center and even ,or the footing moving 3) the subfloor shifting over time causing the hearth piece only to move.

If the chimney or its footing has caused the movement there will be quite a few bricks with cracks. they will usually be in large groups.

 

[begreen]

The hearth appears to be what is settling. It is not parallel to the floor. Does the hearth continue through the floor? It looks poorly supported. Can you post some pictures of the underside from in the basement?

 

[Willkellysims]

Here are some pictures of what we have going on underneath. It's really hard to get a clear pic with the insulation in the way and the board that is going across . I am sure there will be some questions... I will try my best to explain. Pictures are pretty much looking straight up where the hearth is sitting above. This first pic is looking up but a little ways back to give you a little better idea of what your looking at I hope .

 

[Willkellysims]

There are only really 3 or 4 things that can be happening. Chimneys are built on a footing that is independent of the house foundation. 1)Chimney footing shifted/settled, which caused the chimney to move away from the hearth piece. 2) The chimney has leaned away or sideways from the house(usually due to poor constructon like bricks not laid all on center and even ,or the footing moving 3) the subfloor shifting over time causing the hearth piece only to move.

If the chimney or its footing has caused the movement there will be quite a few bricks with cracks. they will usually be in large groups.

On the inside we do not see any bricks (the fireplace nor hearth piece) with cracks;

 

[begreen]

The underside hearth support looks wrong. It looks like it's depending on cantilevered blocks. Some are not even attached to anything.

I would remove the entire hearth step and then decide on a couple options. One would be to rebuild with much better support. Bring in a pro-mason for this, at least for a consultation. But another option would be to lower the hearth to floor level with a different covering than brick. Think a large piece of bluestone or it could be insulated with a layer of cement board and tiled. Then, consider putting a freestanding, rear-exit stove on this new lowered hearth for some real heat and lasting warmth.

 

[Willkellysims]

The hearth appears to be what is settling. It is not parallel to the floor. Does the hearth continue through the floor? It looks poorly supported. Can you post some pictures of the underside from in the basement?

the hearth does not continue through the floor. It just sits on top of it.

 

[kennyp2339]

I would rip out the old separate hearth, install durarock and tile in its old place, if you put an insert in the fireplace, then the tile in front could act as the ember shield. its the cheap and easy fix, plus you then could remove the support underneath.

 

[brad wilton]

what begreen said would be easiest solution.but you also said it's not safe to burn with could you explain?

 

[Willkellysims]

I retook some pictures now that it is brighter, hopefully these will be better for you. All the stuff on the hearth is the old mortar that has crumbled and is falling out. We even pulled out newspaper that was wadded up and stuck to this sandy mortar stuff as though someone had stuffed newspaper down in the hole then covered with the stuff that is crumbling. HA newspaper is dated July 8 1989.

 

[begreen]

the hearth does not continue through the floor. It just sits on top of it.

Are you sure? It appears to be cut in and going below the floor on the front edge.I suspect the hearth is relying on the cantilevered cement blocks for support, but they don't go all the way across so the front edge is unsupported.

 

[jatoxico]

The hearth appears to be what is settling. It is not parallel to the floor. Does the hearth continue through the floor? It looks poorly supported. Can you post some pictures of the underside from in the basement?

I agree with that, just didn't (don't) want to make too many assumptions especially since that amount of brick on an outside wall (right next to the foundation isn't really all that much weight. Seeing the pics from below explains why.

Removal of the hearth and installing a freestander like BG suggested is exactly what came to my mind as well.

 

[begreen]

You might speak to your realtor and ask if the owners signed a defects disclosure form. If this was obvious it should have been disclosed.