Thanks for the suggestion.

The issue appears to derive from the fact that our web pages are published with .tpl (template) extensions, which are rewritten via PHP to include pricing information, then presented to the browser with an .html extension.

Thank you for your kind advice. Unfortunately, the result remains the same ...
http://www.just-insulation.com/002-brands/armaflex.html?file=armaflex

I have completely rewritten my web site, adding structure to the file directories. Subsequently added was Redirect information within the .htaccess file.

The following example ...
Redirect 301 /armaflex.html http://www.just-insulation.com/002-brands/armaflex.html
Returns this response in the URL bar of ... 
http://www.just-insulation.com/002-brands/armaflex.html?file=armaflex
I am at a loss to understand why the suffix "?file=armaflex" is added

The following code is inserted at the top of the file ...
RewriteEngine On

redirect html pages to the root domain

RewriteRule ^index.html$ / [NC,R,L]

Force www. prefix in URLs and redirect non-www to www

RewriteCond %{http_host} ^just-insulation.com [NC]
RewriteRule ^(.*)$ http://www.just-insulation.com/ [R=301,NC]

Any advice would be most welcome.