Expert: Richard Taylor, AIA - 5/9/2004

Question
Hi Richard:

I think I sent you a different question last week.  I have two new topics to ask about today.
I am rehabbing a house and want to replace or dressup the storm windows.  Is there a good (that is effective and inexpensive)way to clean all of the weathering and rust pits on the surface of aluminum storm windows to make them look nicer.  Any suggestions would be appreciated.

Also, I have always been a little confused about waterproofing of foundations. I work with Habiat for Humanity one or two days a week and yesterday we installed some plastic sheet material against the outside concrete basement walls.  The material had dimples so that there would be an air space between the plastic sheet and the cncrete walls.  The sheets were glued to the walls at an elevation six feet above the footings and the plastic hung down to just above the top of the footings.  What exactly is this plastic sheeting accomplishing?  why isn't the sheeting required to go down over the footings and why isn't it then sealed or glued to the top of the footing?  Theoretically, water will leak through cracks in the basement wall if the plastic sheet is not there?  Why is an annulus or air space required between the plastic and the concrete wall?  Is the concrete considered to be so porous that moisture could migrate through the concrete without the plastic protection?  Anyway, As thorough as you care to be, I would love to understand what is going on regarding waterprooing concrete basement walls.

And as always, thank you very sincerely for your thoughts and effort answering my questions.        

Regards,

jeff Pierson

P.S.  I really do kno how to type.  My keyboard is in really poor shape and it continues to not type letters after I have depressed a key.  I have to go back and corrct about every other word.  I may miss one or two errs, but I hope my question is readable.

Answer
Jeff:

Thanks for your questions!

Here's some info on cleaning aluminum windows:

Cleaning Aluminum Window Frames

If painted, use a solution of mild detergent and water, or a mild commercial cleaner whose label says it is safe for painted surfaces. Always rinse off solution. Wipe off excess water with a dry cloth. Do not use strong cleaners or scouring powder as these will damage the paint. If you plan to clean window frames, do it before cleaning window glass so solution does not spot glass panes.

Clear or colored anodized aluminum resists weathering, and can be washed with mild detergent and water like painted frames. Solvent cleaners can be used to remove grease spots from anodized frames. Never use abrasives on either anodized or painted surfaces as they will scratch it.

Bare, unfinished aluminum gradually weathers and turns gray. It forms its own oxide coating which protects it. (A coat of clear lacquer will prevent this.) In early stages of weathering, washing with soap and water will restore brightness. If you want to restore brightness when it has weathered more, stronger cleaners or mild abrasives will be needed. Test any new cleaner on a hidden spot to be sure it will work satisfactorily.

Do not clean aluminum if it is too hot to touch, or if temperature is below 50 F. Always remove all traces of cleaner thoroughly, with water-rinsing, or, if a solvent/wax type by wiping. Avoid excessive use of abrasives which leaves permanent scratches. Badly-weathered window frames may be washed with soap and water, rinsed thoroughly, and painted.

Homemade Window Glass Cleaner

1/2 cup vinegar to 1 gallon of water (or 2 tablespoons per quart)

OR

1/2 cup sudsy ammonia to 1 gallon water (or 2 tablespoons per quart)

OR

1/2 cup sudsy ammonia 2 cups rubbing alcohol 1 teaspoon liquid dishwashing detergent 1 gallon water (This one is less likely to freeze in cold weather.)

Regarding waterproofing foundations, the plastic sheeting does two things.  First, it acts as a barrier against direct water infitration from hydrostatic pressure against the wall.  Second, holding it away from the wall (the purpose of the dimples) allows any condensation to run down the inside face of the sheet and out at the bottom of the wall.  If it were attached at the bottom, the condensation couldn't run out.

The bottom of the sheet, while not all the way to the top of the footing, is nevertheless below the top of the interior slab.  This allows water that rises under the slab to pass through the weeps at the bottom of the wall and into the foundation drain outside the foundation.

Yes, concrete is porous and can allow water to pass through.  In fact, when it's dry it wicks water right in, so the waterproofing is essential, although in this case, you're working with a very minimal WP system.

Hope this helps!

Richard Taylor, AIA
Richard Taylor Architects, LLC
www.rtaylorarchitects.com