A Carpenter’s Journal

March 10, 2010

New Construction Windows

Filed under: Windows and Doors — Tags: , , — Fran Maloney @ 3:35 pm

New construction windows differ from replacement windows in that they are not installed within the frame of an existing window.  They are complete weatherproof units which have a flange or casing attached to the frame on the exterior side.   Building paper or waterproof membrane is applied to the sides of the rough opening and the window is installed square, level and centered in the opening.  They are fastened with nails or screws through the casing or the flange. 

You can still get the older style windows with an exterior sill and casing applied at the factory but most newer aluminum or vinyl clad windows do not come with casing or sill.  It is possible to bring your siding right up to the frame of a clad window which leaves a thin but weathertight edge visible around the sash, but, when the traditional look is desired, casing and sill have to be applied in the field as a decorative addition.  We usually use a vinyl “historic” sill attached underneath and then whatever exterior casing we are trying to match on the top and sides.  This new casing must be flashed on the top like on any other window.  Inside, we usually spray expanding foam in the space between the framing and the window to stop any drafts and then trim the inside to match the rest of the house.

Replacement windows are sized by the sash opening but new construction windows are sized in part by the rough opening and in part by the visible glass dimensions.  Most window companies make their new windows to fit pretty closely into the traditional rough openings.

March 4, 2010


Filed under: Materials,Windows and Doors — Tags: , , , — Fran Maloney @ 8:19 am

The National Fenestration Rating Council provides a standardized means for buyers to compare windows and for building officials to regulate insulation values.    A new window with insulated glass will have a sticker attached to the glass which has the energy ratings for that window.   Two of the most important numbers to know when buying a window which are on that sticker are the U-value and the Solar Heat Gain Coefficient.  The U-value is the inverse of the rate of heat flow through the glazing; the smaller the u-value, the better the insulation quality of the glass.  The Solar Heat Gain Coefficient is a measure of the amount of radiant heat that is transmitted through the glass; the lower the SHGC the less of the sun’s heat will come through the window.   A low SHGC will reduce air conditioning expenses in a hot climate but actually may be counterproductive in colder areas where you might want the heat gain in the winter more than you would want the protection from the sun in the summer.  For a look at the sticker and for a better explanation of the numbers on it you can go to the NFRC website here.   http://www.nfrc.org/label.aspx

The NFRC also has a search page where you can look up the energy numbers on any window manufacturer’s products at: http://search.nfrc.org/search/searchdefault.aspx

There is currently a federal tax credit in place of one third the purchase price for qualifying windows and doors up to $1,500.00.  To meet the qualifications for the credit the window needs to have a U-value of .30 or less and a SHGC also of .30 or less.  Most of the standard windows do not have U-values quite this low, but many manufacturers have product upgrades that meet the criteria for the credit.  The tax credit is actual tax off your tax bill so it is a major incentive to the purchase of new windows.  It is due to expire at the end of 2010, it can only be used once over 2009-2010 for all qualifying energy upgrades and it does not include installation costs.  For more information on the credit you can go to the Energy Star website:  Energystar.gov.

March 3, 2010


Filed under: Uncategorized — Tags: — Fran Maloney @ 9:53 pm

I had the chance to use Mike’s Festool today to make doors for the storage and access areas in the basement office we are working on.  Festool is an expensive German made system for using a circular saw to cut straight lines with little or no tear-out in the material you are cutting.  It consists of a specially designed saw and an aluminum track that it fits into.  The saw has a plunge function, the blade automatically retracts below the base when you take the pressure off of it and it has a small flat piece of aluminum that emerges behind the blade when it is plunged into the material you are cutting.  I am not sure what the function of the small piece is but it looks like it might stabilize the blade in the cut.  The track that the saw fits into is made of aluminum and has soft rubber grips on the underside so that when you put the track down on the material it stays put.  The blade of the saw cuts exactly along the edge of the track so that it is very easy to tell where the cut will be and easy to position it in any orientation on the material;  unlike a table saw, opposite edges do not have to be parallel.  The track also holds the material precisely where the blade is cutting up so that there is no tear-out.  I made my first set of doors with the miter saw and the table saw in lumber core birch.  There was some tear out with both these saws  but none with the Festool.   I found it actually easier to use than a table saw or a miter saw for this type of cutting.  If business ever springs back to life, I might put this on the list of tools I’d like to own.

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