renovating existing 1820s house

[Ben29]

I'm working on this 2-story, wood-framed house that was built in 1820's. The existing structure seems sturdy however there are cracks in the ceiling and the wood-framed floors aren't level. I am tasked with putting a 10' wide opening in the interior bearing wall. The contractor already added a new rear addition to the house early this year.

Also, the existing basement has a dirt floor and the basement is pretty humid. I am unable to observe the underside of the first floor framing because it is covered up.
Post shores were placed throughout the basement to help support the existing floor joist, which I assume were deflecting. I suspect that the existing floor joist are not in good condition, though I cannot actually see them. I am installing new wood posts in the basement (with new footings) as needed to support new jamb studs above. The owner doesn't want to do more work than he has to, but obviously they are relying on me to give good structural direction where appropriate. The existing post shores are not code compliant. I am not sure how they passed the home inspection.

1)Do you think I need to specify a rat-slab in the basement? Is it OK that I leave the dirt floor?
2)What should I say about the existing floor joist? They don't want to replace the joist if they don't have to, but I am unable to observe them currently. I suspect that they are in poor condition due to humidity and bearing directly on stone foundation wall for 200 years.
3)What CYA note can I put on my drawings so that I don't get pinned for the existing ceiling cracks and floor levelness?
4)New wood-framed knee walls were placed in the attic to support the roof. It is unclear to me whether they replaced old knee walls. I believe that the knee walls are causing the existing ceiling joist to deflect, thus causing cracking in the ceiling below.
4)I think I need to tell them to remove the existing (non-code compliant) post shores in the basement and install new first-floor framing. Do you agree?
5)Also the brick chimney is leaning terribly in the attic.

 

[Ben29]

Here is an elevation view of the new opening located in the interior bearing wall.

 

[XR250]

Sounds like you need to have a conversation with the owner or contractor and limit your scope of things with a solid contract.
An 1820's house is a can of worms (or termites). Someone has to decide where you stop tinkering.

 

[Ben29]

Basically, there are a few things about this house that are structurally questionable, but are not directly related to the reason I was hired. I was hired to design an opening in an existing bearing wall.

I am not sure what all I am obligated to address, and how I should address it. If they hired me to provide permit drawings for the opening. Do I need to address the other issues on those drawings? Or can I write a letter stating the additional issues that I see with the house?

 

[LuK13]

"The owner doesn't want to do more work than he has to" = probably shouldn't have have bought a house from the 1800s... Restoring and modifying these structures is a labor of love, and usually a very poor investment. You probably need to have a "come to Jesus" talk with the owner at some point.

My guess is untreated lumber with no capillary break bearing on that foundation has rotted and lost enough of the bearing surface to cause the sloped floors and possibly a dangerous situation. That photo of the new post at the beam pocket and the effloresce where the beam enters the pocket? You could probably break that bearing end of the beam up by hand at this point.

The corbeling on that chimney is wild. I have seen an older chimney like that finally give up and fall through the ceiling. Previous owner had demoed it to below the roof, but with no attic access the new owner didn't know the chimney existed until it fell into the living room.

Your concern about the knee walls and cracked ceilings makes sense and I have seen it before myself.

IMO your obligations are:
1. Whatever you are modifying, and the entire load path to ground for anything that you modify.
2. Any unsafe or dangerous conditions you observe, as you have an obligation for the publics safety. The International Existing Building Code has definitions of unsafe and dangerous you can use as guidance.

If you go in with blinders on to keep costs down and something does happen you will still be the last design professional to put your name on this building. Even if you exclude certain things and blanket your work with CYAs you could still get named in a suit and it will cost you time, money, and stress to get removed from that suit.

You may want to consider walking away if the owner is too cheap. Once things are opened up you are almost guaranteed to find something. Even if the construction was perfect in 1820, in 200 years it only takes one neglectful owner to cause problems.

 

[XR250]

If you go in with blinders on to keep costs down and something does happen you will still be the last design professional to put your name on this building. Even if you exclude certain things and blanket your work with CYAs you could still get named in a suit and it will cost you time, money, and stress to get removed from that suit.

This is an issue on any renovation and is a risk we take. Even if you don't see it, you can be named in a lawsuit. This is why we have contracts and insurance. However, if I do see something that I consider life-threatening, I will make an issue out of it.

 

[GeorgeTheCivilEngineer]

Props onto concrete blocks *shudder*

This is the sort of job that can't really be done on the cheap.

I would echo what others have said about being wary and that you can't just ignore life threatening problems. Clearly their temporary works so far isn't adequate.

UK terminology doesn't necessarily translate perfectly so I may have misunderstood some of the questions, but this is my 2 sterling pence worth.

1)Do you think I need to specify a rat-slab in the basement? Is it OK that I leave the dirt floor?
Not necessarily if it isn't going to be used. I am generally reluctant to underpin unless absolutely necessary.

2)What should I say about the existing floor joist? They don't want to replace the joist if they don't have to, but I am unable to observe them currently. I suspect that they are in poor condition due to humidity and bearing directly on stone foundation wall for 200 years.
Well, needs inspecting. I'd be comfortable specifying a replacement of the end of the joist if it is only the end which has decayed. Whether they want to do it or not is on them.

3)What CYA note can I put on my drawings so that I don't get pinned for the existing ceiling cracks and floor levelness?
When forming an opening in a stone wall it is very hard to avoid cracks. There are cracks already so make them aware making good will be needed. It may be a rubble infill wall so the needling scheme needs to be very closely spaced and done very carefully.

4)New wood-framed knee walls were placed in the attic to support the roof. It is unclear to me whether they replaced old knee walls. I believe that the knee walls are causing the existing ceiling joist to deflect, thus causing cracking in the ceiling below.
Well that's not ideal.

4)I think I need to tell them to remove the existing (non-code compliant) post shores in the basement and install new first-floor framing. Do you agree?
I like to retain and strengthen what you can (history of working on listed/heritage structures). Again, if removing a floor you potentially remove restraint to the stone wall. While they are thick, rubble filled walls don't hold together all that well so I would not want to remove all the first floor in one go.

5)Also the brick chimney is leaning terribly in the attic.
Yeah I'd be asking for a mason to patch that up possibly with steel supports. I'm not sure which bit is leaning - if you mean how it's built then I'd factor in how long it's been like that and what is the cause of the distress?

All you can do is highlight the hazards and even if you don't specify a repair, it is minimal time to suggest a safe method.

 

[Ben29]

Luk & XR250,
Thank you for your input. I went ahead and issued a contract stating all of the items that are of concern to me, and specified exactly what my scope is. I also stated that the brick chimney needs to be removed because it is a life-threatening condition.

 

[LuK13]

Ben,

XR250's post made me reconsider my original post. My original post was heavily influenced by a recent interaction I have had. You are in the best position to judge your client and how reasonable they may or may not be.

So now that I have mellowed out a bit from the morning here is some more focused advice.

1. That chimney may not need to be removed, but at least needs further examination. Early 1900s is when I start to see unlined masonry chimneys. Clay flue tile existed, but I don't think they became common place until like 1920s or 30s, at least where I am at. Next question is what kind of shape is the crown in? is there a cap? If the chimney is unlined, the crown is deteriorated, and has no cap, then that masonry has been exposed to the elements and the mortar is likely shot from the inside out. Maybe a previous owner had a liner installed? a cap put on? it might not be a total loss, but someone needs to get eyes on it. Based on your latest post, the horse may already be out of the barn on this one.

2. Basement rat slab? not required, but the intended use of the space should be considered. If you are gonna put a vapor barrier down a rat slab could be a good way to protect the vapor barriers integrity even under light traffic since this is a basement and not a crawlspace. The basement moisture issue is more of what I would call a "system" issue, and just adding a rat slab isn't going to be a complete fix.

3. For floor joists I think you are probably looking at opening the basement ceiling to provide a load path from the header of that new opening. If any of those joists are in need of repair then you deal with those when the time comes. In regards to my "blinders" comment, I am not advocating that you drop the whole ceiling and go fishing for problems, I just had someone ask me to ignore something that was in plain sight and you cant do that. It would be worth while to inform the owner that the other unobserved floor joists are likely in a similar condition and destructive examination is required to confirm this if they want to pursue it. That is a good notification to have in writing as a CYA.

4. For CYA I would put together some sort of pre-work inspection that lists the existing conditions with a few photos. I know a number of contractors that take before photos just incase there are any questions later. If you aren't going to be compensated for the work, maybe skip the formal report and just do a short list like you already have and keep the photos as backup.

5. The knee-walls you could say something about, but it sounds like they are not related to the new opening. These are a good candidate for the "ignore" list unless it is obviously dangerous, like a ceiling joist is subject to collapse.

6. All of the shoring is visible and I believe within your responsibility to address as it is in the area you are working. I have met people that are all over the spectrum on shoring like this. Some think its A Okay, others might wince at the jack posts and want lally columns with a proper footing, and some want to replace framing rather than shore it up. I think for you the key question is what kind of shape is that beam under the openings in? That would be where I would start to try and decide lally columns and footings only vs new floor framing.

 

[dik]

Renovating? or restoring?

So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[Ben29]

George & Luk,
Thank you very much for your thoughtful write-ups! This is extremely helpful.

 

[BAretired]

The new 10'-0" wide opening removes a significant chunk of the existing bearing wall, which was also a shear wall. New frames should be designed to resist lateral forces as well as gravity loads.

The sloping chimney, as it now exists, adds a horizontal shear between the attic floor and roof which appears to be resisted by rafters. That is a potentially dangerous situation. I agree that the chimney should be removed.



BA

 

[LittleInch]

I'm no structural engineer, but my issue for you is that in something this old that has been hacked around with and had all manner of dodgy repairs and sticking plasters is that your quite significant works will inevitably have an impact on the loads and stresses somewhere else in the building and any subsequent cracks, failures or whatever will be blamed on you regardless of what you write in the contract.

It may have stood there 200 years, but that doesn't mean it will still be standing in 20 years if you do all these changes to it.

I agree with others that chimney looks like it is about to collapse and is clearly showing signs of water leakage.

Old houses are a minefield. You think you've navigated a way through then the mine that wasn't on the plan blows your foot off...

I agree with LuK13, though not quite sure what a come to Jesus talk is.... Two hundred year old house are not for the faint hearted or simple just knock a wall or two down merchants. Everything crumbles to dust eventually....

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[WinelandV]

Two hundred year old house are not for the faint hearted or simple just knock a wall or two down merchants.

But Bob Villa made it look all so simple on This Old House.

Please note that is a "v" (as in Violin) not a "y".

 

[LuK13]

LittleInch,

At least how it has been used around me, a "come to Jesus" talk means its time to "see the light [truth]".

My first impression of "The owner doesn't want to do more work than he has to" was that the owner was being cheap and trying to avoid work wherever possible. Since then I realize that the owner may be well aware of what lies ahead and have a plan to address numerous issues, and for scheduling or financial reasons would just prefer this job doesn't have a lot of scope creep that blows up their plan.

I have been in situations where the design drawings are a mess, all the subs submit hundreds of RFIs in the first month, and the design team is radio silent. The contract required response times on RFIs gets blown out of the water, the owner wants 0 schedule slip, and the architect is bitching about how they don't have a budget for this much work in their fee. Next thing you know there are big picture RFIs about code compliance that are 6 to 9 months old with no response and everyone is running out of work to push forward on. Then the GC has to drag all of the involved parties into the trailer for a "come to Jesus" talk to say this shit isn't going to work and something needs to give going forward, that's just reality and everyone here needs to accept it and agree to a resolution.

To me the key component is at least one stakeholder has been willfully ignorant which has been harmful to the team and/or process, and they need to "see the light" before things can move forward in a reasonable manner.