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Davenport Chimney, Hiding Mechanical Appendages, Problems

Posted: Sat Apr 22, 2006 4:53 pm
by pharding
The chimney on the Davenport House is 105 years old. It has never had a chimney cap. I really do not want to put one on now. How critical are they?

I have 5 flues in the chimney. Are there any problems with using them as follows?

1. First floor fireplace

2. Kitchen exhaust hood vent

3. Plumbing vent in one.

4. Basement high efficiency gas furnace and hot water heater.

5. Attic high efficiency gas furnace.

How important is it to use flue liners? I am inclined to use Solid/Flue a "cast-on-site" liner in the flues for the high efficiency gas furnaces because the burn so hot.

Posted: Sun Apr 23, 2006 8:46 pm
by PSTraveler
Dear Paul,

I'm not an expert, but I believe that high efficiency furnaces produce flue gases that are cooler than older furnaces. The result is that significant condensation can develop, which (in addition to being very acidic and corrosive) can damage masonry chimneys in freeze/thaw cycles. Not only that, but since the flue gases are so cool, they may not create sufficient draft and furnace inefficiency or even carbon monoxide poisoning can result.

A liner can effectively resize the flues so that the draft is better, as well as protect the masonry from condensation damage. You should look for a respected chimney expert in your area, or a qualified HVAC contractor to advise you.


Chimney Update

Posted: Thu Apr 27, 2006 7:32 am
by pharding
We are now trying to do the following to avoid and minimize mechanical and plumbing penetrations of the roof.

1. The chimney flue for the fireplace currently is unlined by any material except for brick and is slightly less than the recommended cross sectional area. I am looking at two options. A. Leave as is and minimize use. Or B. Consolidate its flue with an adjacent abandoned flue by removing a wyth of brick acting as a divider and lining the consolidated flue with a proprietary cementious product. Option B. while being the better solution will probably not happen for cost reasons.

2. One flue will be used for combustion air exhaust for the attic high efficiency mechanical unit. Combustion air intake would draw air through the unheated attic area from the new ridge vent. We are working through this with the manufacturer's technical staff. We may do this and classify our efforts as being experimental and see if it works. Once implemented I will find out next winter if this works.

3. One flue will be used for a plumbing vent.

4. One flue will be used for a gas hot water heating vent.

5. The kitchen range exhaust hood cannot get to the chimney. It will be routed down and out through a reused 1901 coal or ice access portal. It is roughly 24" by 24". We want to retain this original opening because it is part of the original fabric and story of the house. The exterior frame of the opening will be retained. The recessed door will be removed and saved. Wood batten strips were used on two south facing basement windows as a vertical wood screen, similar to vertical wood balusters / interior and exterior wood screens. We will repeat this detail here to mask exhaust vents for the following: kitchen exhaust hood vent, powder room exhaust fan vent, and dryer exhaust vent.

6. The other plumbing vent is in its original location as built in 1901. It is tucked away between the bathroom dormer wall and the dormer overhang. FLW was exceedingly clever in putting it there originally. It gets Greeked out and is semi-concealed in this location. If you study the house and look hard for it, you can see it just barely. Other observers will never notice it.

7. The second floor bathroom exhaust fan will be routed through part of the new 1" wide continuous eave vent.

8. The condensers for the new high efficiency HVAC units will located in a new below grade areaway adjacent to the house.

9. The electric meter will be mounted on the restored/rebuilt 1921 garage in the summer of 07. Electric, telephone, and optional cable service will run underground to the house from the garage.

10. I will work with the gas company to relocate the gas meter so that it is concealed.

11. We use satellite TV. The dish will be on the roof of the garage.

12. The basement high efficiency furnace will have its venting for combustion air exhaust and intake concealed by cutting 1" high slots beneath an angled exterior wood trim board 18" above grade. This will be invisible to everyone except those laying on the ground next to the south facade.

Summary The roof and all exterior facades will be as pristine and free of mechanical intakes, exhausts, vents, condensers, power cut-off switches, electiric meters, gas meters, satellite dishes, overhead power lines, overhead telephone lines, overhead cable tv ines, etc. as it was when built in 1901. This has been extremely difficult to pull off.

Meeting with the Solid/Flue Rep and More Challenges

Posted: Mon May 01, 2006 7:51 am
by pharding
Saturday I met the representative from Solid/Flue a "cast-on-site" liner for the flues in the chimney. He and I climbed up on the roof to visually inspect the flues of the chimney. Unfortunately it was not a pretty sight. The chimney when originally built was not lined with clay tile. Each flue has a brick lining with mortar with what appears to be some open joints. Not good. I am now being forced to line it.

Unfortunately I did not have a line item for this in our project budget. This could be a major bite out of the contingency. Now I know what an architect's client feels like when finding the inevitable substantial change order. It reiterates the importance of a reasonable contingency when doing restoration. As an architect sometimes I experience clients who balk at budgeting a reasonable contingency. In restoration, regardless of how thorough the construction drawings are, a contingency is critical.

So now it boils down to the cost of Solid/Flue versus the more common stainless steel liner approach. I will probably decide by Friday.

Another challenge has reared its ugly head. The neighbors are getting restless. The owner to the south, with whom we share a common driveway, has organized some of the neighbors in opposing the restoration or more specifically the pace of restoration. She has approached all the neighbors in attempting to organize opposition and apply pressure to the building department. She was foolish enough to approach the owners that are restoring Drummond's River Forest Women's Club and ask him to the join the merry opposition. He explained that since we all live in a historic neighborhood that historic preservation goes with the territory and that given the scope and quality of our work that we were moving at a reasonable pace. My wonderful neighbor to the south, with whom we share the driveway, has appointed herself as the self-appointed representative of two blocks of our street. Unfortunately or fortunately she has all of 5 homeowners that support her opposition. As an architect, I have heard this type of nonsense before and I know that this too shall pass. She is more of a nuisance than a problem. Diplomacy and tact are the words of the day for this nuisance. Bend but don't break.

Meanwhile restoration rolls on. Second floor HVAC was unbelievably difficult. There is simply too little space for our modern technology. We had numerous meetings with the HVAC subcontractor to work this out. Now the attic HVAC work including ductwork is 90% complete. It was like putting a watch together instead of normal contraction. It is turning great, except for one problem. Unfortunately one run of ductwork installed Friday blocks out the installation of 65 square feet of insulation in the attic. This will necessitate uninstalling a run of ductwork so that we can get the insulation in there. This was discovered Saturday.

Saturday was not a good day for the restoration. On Saturday I discovered the poor condition of chimney, extent of the organization of the opposition to our wonderful restoration, and ductwork blocking out the insulation. Maybe I should be worried. But I am not. These are just minor speed bumps on the way to a wonderful restoration of an important architectural work, by the greatest American Architect, that was grossly disfigured in 1931.

Posted: Mon May 01, 2006 4:13 pm
by flwright

I cannot agree more with building a contigency into every project, and I am still surprised that there are clients who are unwilling to add this in for their own safety and protection. I must sympathize with you, however -- it must have been difficult coming up with a good contingency figure for a FLW home! In our office, we tend to have difficulty settling on a decent number for standard renovation / restoration projects, let alone dealing with some of the unique circumstances that Wright would have built into his projects.

A few questions on this topic (if you don't mind...)

1) At what percentage of the overall budget did you set the contingency?

2) What remains of the contingency at this stage of the project?

3) Although I am sure you did exhaustive research prior to beginning the project, have you found that your research or construction documents have missed anything that would have helped you through the process?

4) What surprises have you encountered throughout the project (other than those listed above)? Any uniquely unforseen Wright-induced problems?

Keep up the excellent work and don't let those pesky neighbours bother you. Just make sure their movement doesn't gain any momentum! Removing construction grime with complimentary car washes and yard maintenance goes a long way to keeping people quiet and happy!

Posted: Mon May 01, 2006 10:50 pm
by pharding
flwright wrote:
1) At what percentage of the overall budget did you set the contingency?
Background information to provide a proper context for my answer. My firm carries two types of contingencies: design and construction contingencies. With the design contingency we carry a larger contingency initially and we gradually reduce it as the drawings are further developed. On a large, $10 to $20 million, new project we carry 10% in schematic design. At the end of design development we will reduce the contingency with the cost projection to 5%. We also typically carry a 5% construction contingency which breaks down as follows. Architectural and engineering change orders: 3%; owner change orders 1%; building department: 1%. We have never been over 1 1/2 to 2 % for architect and engineer items on large new buildings. On a comparable large renovation project we would typically double the above percentages.

During design on our FLW restoration project, I included a 30% design contingency plus 25% for a construction contingency. After my experience on Davenport, when working for a client I would reduce those percentages.

flwright wrote:2) What remains of the contingency at this stage of the project??

7% with the scope very well defined. We are four months from substantial completion with approximately 40% of the work to go. The contingency is now approximately 15% of remaining construction funds.

flwright wrote:3) Although I am sure you did exhaustive research prior to beginning the project, have you found that your research or construction documents have missed anything that would have helped you through the process??
The biggest sources of our Davenport change orders were due to scope creep, quality creep, and concealed conditions. As an architect working on my own restoration project, it was difficult to do anything to less than the highest standards. The most expensive change orders were: increased scope of structural repairs that I added and a major increase in scope to erase the 1931 alterations and restore the roof and front facade to FLW 1901 design as it was built. Restoring the facade and roof to 1901 was approximately a $100,000 change order plus $30,000 for the future front terrace.

flwright wrote:4) What surprises have you encountered throughout the project (other than those listed above)? Any uniquely unforeseen Wright-induced problems??

Number 1: How much it cost to properly restore a FLW property.

Number 2: How much I enjoyed doing it.

Number 3: How much time that it takes to do it.

Number 4: How much FLW pushed the limits of construction technology.

There were too many problems to list here. It seems that just about everything about the 1901 E. Arthur Davenport is unique and special compared to contemporary houses of that period. It was designed to the nth degree. It was not worked out technically to that same degree. The house was built with a limited budget using less durable materials. The house had never been restored and had a lot of deferred maintenance. The economic challenges have been substantial as a result of these factors.