Wright Chat

I am living in my father's home, the Robert LLewellyn Wright home, built in 1958. Recently in heavy and/or sustained rain we have experienced leaks at the edge of an upstairs bathroom and at the bottom of an interior!! concrete block wall in our basement. These are not leaks through the roof, but appear to be caused by flow of water through the concrete block. I have had some repointing of block adjacent to the chimney mass, but that has not solved the problem.



My solution would be to waterproof the concrete block over a large area covering the point where the water appears to gain entry. Is this feasible? I would appreciate advise on how to solve this problem.



Thank you

Is this concrete block wall exposed to the exterior? And if so what is it exposed to? Is this wall above grade or below grade?

Try Thoroseal. Available at building materials supply houses.

pharding wrote:Is this concrete block wall exposed to the exterior? And if so what is it exposed to? Is this wall above grade or below grade?

Thank you for your response. It turns out that, as it continues to rain, this is a much bigger problem than I thought. We have leaking into our kitchen where the block meets the ground, in the basement adjacent to where a buried electrical conduit comes in, as well as in an upstairs bathroom at the intersection of the kitchen mass where the block is exposed to the air outside and is adjacent to a new roof (also exposed to air) on the inside.



The explicit answer to your question is that most of the concrete block is exterior/interior walls exposed to the air, but the block adjacent to the basement extends underground. I think there is leaking wherever unsealed block can transmit water to the interior, particularly at ground level, roof level, and underground where the wall is penetrated, as by the electrical conduit.



This problem has developed within the past 18 months, so it seems to me that a major repointing and waterproofing job is needed. What do you suggest?

Without seeing the existing conditions, it is impossible to recommend the optimal solution. Below grade concrete block is problematic unless a membrane waterproffing is used. Any other type of waterproofing does not offer long term durability. If one installs membrane waterproofing it is also generally advisable to install pvc perforated drainage tile to carry the water away from the house. Do not connect it to a sump pit within the basement. The concrete block adjacent to the new roof may be leaking because of improper flashing. Be careful with repointing masonry joints. Generally if a mason is working for an owner without an architect, the masons butcher the joints and wreck masonry. Typically they carelessly and quickly grind the joints creating fat and uneven joints. The results are almost always terrible.



I recommend hiring an architect. Contractors are generally terrible about objectively recommending appropiate solutions to water/moisture penetration problems.



E-mail me for more information at [email protected]

DO NOT seal concrete block if you are in an area that has any freezing and thawing potential. Great damage has occurred when people try to seal concrete materials with a sealer in these zones. Water will still get into the concrete (even a little) and get trapped due to the sealer. The freezing and thawing cycles WILL destroy the concrete.



This happened to Fallingwater many years ago when they tried this, and several other structures on various building since (some Wright buildings as well). There are sealers available and they work fine for areas in regions that don't get near freezing zones.



Wright's Florida Southern University was experimenting with these, but at the FLWBC Conference a few years ago, architects and engineers talked about "sealing concrete" but there were some experts there that were very quick to point out that this is only a viable application in warm, non-freezing areas like Florida. They warned in no uncertain terms about the imminent failure and destruction of concrete structures and materials that had been sealed where even occasional freezing could take place.



Just a recommendation, but you may want to contact Lauren Burge (who I know knows a lot about this). Her address is :



lburge AT cmbarchitects.com

Please check out Preservation Brief #39. National Park Service Preservation Brief, Controlling unwanted moisture conditions in historic buildings before using a modern method which is not tried and true for a historic building.



D. Shawn Beckwith

The Durable Slate Company

www.durableslate.com

I just got back from the FLW Conference in LA. Technical experts there were emphatic about not sealing concrete block. Please do not seal the concrete block. Trapped moisture will ruin the block with time.

A waterproofing mastic that went on about 35 years ago has turned out to be one of the biggest problems for Ennis, even though it doesn't face freeze-and-thaw cycles. The inevitable holes that have shown up in the coating have absorbed water, which the coating then holds in, exacerbating the rusting of the rebar. It looks terrible, too.



Peter

Hi Tom -



Tim and Elizabeth were here at Unity Temple last week and we had a fine time. They mentioned that there is a preservation easement on the house owned by the FLLW Building Conservancy.



The Conservancy can provide you with expert assistance as regards these problems and it would be good to consult them, anyway, before major repairs are undertaken.



Best of luck,



Keith Bringe

Executive Director

Unity Temple Restoration Foundation