Each episode includes Tim's own Binford-sponsored home improvement show, called Tool Time, a "meta-program," or show-within-a-show. In hosting this show, Tim is joined by his friend and mild-mannered assistant Al Borland (Richard Karn), and a "Tool Time girl" first Lisa (Pamela Anderson) and later Heidi (Debbe Dunning) whose main duty is to introduce the pair at the beginning of the show with the line "Does everybody know what time it is?" The Tool Time girl also assists Tim and Al during the show by bringing them tools.
Although revealed to be an excellent salesman and TV personality, Tim is spectacularly accident prone as a handyman, often causing massive disasters on and off the set, to the consternation of his co-workers and family. Many Tool Time viewers assume that the accidents on the show are done on purpose, to demonstrate the consequences of using tools improperly. Many of Tim's accidents are caused by his devices being used in an unorthodox or overpowered manner, designed to illustrate his mantra "More power!". This popular catchphrase would not be uttered after Home Improvement's seventh season, until Tim's last line in the series finale, which are the last two words ever spoken.
Tool Time was conceived as a parody of the PBS home-improvement show This Old House. Tim and Al are caricatures of the two principal cast members of This Old House, host Bob Vila and master carpenter Norm Abram. Al Borland has a beard and always wears plaid shirts when taping an episode, reflecting Norm Abram's appearance on This Old House. Bob Vila appeared as a guest star on several episodes of Home Improvement, while Tim Allen and Pamela Anderson both appeared on Bob Vila's show Home Again.
The Tool Time theme music, an early 1960s-style saxophone-dominated instrumental rock tune, was sometimes used as the closing theme music for Home Improvement, especially when behind the credits were running the blooper scenes that took place during the taping of a Tool Time segment.
In the United States, Home Improvement began airing in broadcast syndication in September 1995, distributed via Buena Vista Television (now Disney-ABC Domestic Television) and continued to be syndicated until 2007; in a manner similar to Seinfeld and The Simpsons after they began airing in broadcast syndication, episodes of Home Improvement were not aired in order of their production code number or original airdate. It has previously aired on cable television via TBS from 2002 to 2013, and WGN America from 2002 to 2007. It also aired on Nick at Nite from September 3, 2007 to October 2009 and again on Monday mornings only starting on September 27, 2010, and aired on TV Land from January 4, 2010 to 2013. The show aired on The Hallmark Channel from September 3, 2013 until January 2014. As of January 8, 2016, The Hallmark Channel airs Home Improvement Monday through Friday at 2 p.m. ET until 6 p.m. ET
Since 1995, due to its popularity, reruns began airing on The Disney Channel, Channel 4 and ABC1 in the UK. Originally, Home Improvement was aired on Channel 4 and then later the Disney Channel; however, in 2005, it began broadcasting on ABC1. On September 26, 2007, ABC1 ceased transmissions and no official announcement was made as to which channels would be broadcasting ABC1's previous programming. Although the show stopped airing in the UK due to ABC1 ceasing transmission on September 26, on July 28, 2008 it restarted from the pilot episode on Virgin 1. However, it was announced that Virgin 1 (now Channel One) would close on January 31, 2011, and no announcement has been made regarding which channel the show will be moved to.
In Canada, it previously aired on CTV from beginning to the ending (19911999), CMT and YTV. In Germany and Austria, Home Improvement has been shown in dubbing under the title Hr mal wer da hmmert (Listen whos hammering). It ran on ARD (1993-1995), RTL (1996-2006), RTL II (1999-2000, 2007-2012), VOX (2004-2006), Super RTL (2008-2009), and reruns are currently shown on the private channels RTL Nitro and in Austria on ATV. It was also shown on M-Net on South African television, and reruns are showing throughout 2007 on the M-Net Series channel, available to DStv users. It is previously airing on TV Land at 2AM ET. In New Zealand, reruns of the show also currently play on the free-to-air channel Prime Television. In 2011, Asian Network Star World started telecasting the show in place of The Simpsons.
At the present time, reruns are aired internationally on the Seven Network and 111 Hits in Australia, Sab TV Disney Channel in India and HITS in South East Asia, Hong Kong and Taiwan.