List environment inside the tabular environment: extra line at top preventing alignment

I have a LaTeX question that is bugging me. I have been trying to get a list environment to appear correctly inside the tabular environment. So far I have gotten everything to my liking except one thing: the top of the list does not align with other entries in the table, in fact it looks like it adds one line above the list... I would like to have these lists at the top. This is what I have, a custom list environment:

  \newenvironment{flushemize}{
\begin{list}{$\bullet$}
{\setlength{\itemsep}{1pt}
\setlength{\parskip}{0pt}
\setlength{\parsep}{0pt}
\setlength{\partopsep}{0pt}
\setlength{\topsep}{0pt}
\setlength{\leftmargin}{12pt}}}{\end{list}}


Renamed ragged right:

\newcommand{\rr}{\raggedright}


and here is my table:

\begin{table}[H]\caption{Tank comparisons}\label{tab:tanks}
\centering

\begin{tabular}{p{1in}p{1.5in}p{1.5in}rr}

\toprule

{\bf Material} & {\bf Pros} & {\bf Cons} & {\bf Size} & {\bf Cost} \\

\midrule

\rr Reinforced concrete &\rr  \begin{flushemize}\item Strong \item Secure \end{flushemize}&\rr  \begin{flushemize}\item Prone to leaks \item Relatively expensive to install \item Heavy \end{flushemize} & 100,000 gal & \$299,400 \\ \rr Steel & \begin{flushemize}\item Strong \item Secure \end{flushemize} & \begin{flushemize}\item Relatively expensive to install \item Heavy \item Require painting to prevent rusting \end{flushemize} & 100,000 gal & \$130,100  \\

\rr Polypropylene & \begin{flushemize}\item Easy to install \item Mobile \item Inexpensive \item Prefabricated \end{flushemize} & \begin{flushemize}\item Relatively insecure \item Max size available 10,000 gal \end{flushemize} & 10,000 gal & \$5,000 \\ \rr Wood & \begin{flushemize}\item Easy to install \item Mobile \item Cheap to install \end{flushemize} & \begin{flushemize}\item Prone to rot \item Must remain full once constructed \end{flushemize} & 100,000 gal & \$86,300\\

\bottomrule

\end{tabular}
\end{table}


Thank you for any advice :)

-
Welcome Usagi! Have a look at the answers to these questions: Preventing itemize environment to insert initial vertical space and Including an itemized list within a tabular column using the paralist package. Those might solve your problem as well. –  Stefan Kottwitz Feb 11 '11 at 21:55
@StefanKottwitz, I'll take a look, thank you for the help :) –  Usagi Feb 11 '11 at 22:12

Here the working code. Please also read the links Stefan Kottwitz posted above. I also changed a couple of other things. Please do not write {\bf ...} but \textbf{...}. Note the new columns types. Read the manual for array to learn about them.

\documentclass{article}

\usepackage{booktabs}
\usepackage{xcolor}
\usepackage{array}
% Define your own types for special columns:
\newcolumntype{P}[1]{>{\raggedright\arraybackslash}p{#1}}
\makeatletter
\newcolumntype{F}[1]{>{\raggedright\arraybackslash\@minipagetrue\flushemize}p{#1}<{\endflushemize}}
\makeatother

\newenvironment{flushemize}{%
% You should put this outside the list. The new environment will make them local anyway:
\setlength{\itemsep}{1pt}%
\setlength{\parskip}{0pt}%
\setlength{\parsep}{0pt}%
\setlength{\partopsep}{0pt}%
\setlength{\topsep}{0pt}%
\setlength{\leftmargin}{12pt}%
% Use \list ... \endlist instead of \begin{list} ... \end{list} inside another environment
\list{$\bullet$}\unskip}
{\endlist}

\begin{document}

\begin{table}[H]% Please don't use 'H' or 'h'.
\centering
\setlength{\belowcaptionskip}{\abovecaptionskip}% Correct skip for caption on top
\caption{Tank comparisons}
\label{tab:tanks}% Yes! The \label comes after \caption, not before
%\rowcolors{2}{white}{tableShade}% Always include all packages in your example

\makebox[\textwidth][c]{% Centers an overwide tabular
\begin{tabular}{P{1in}F{1.5in}F{1.5in}rr}
\toprule
\textbf{Material} & \multicolumn{1}{p{1.5in}}{\textbf{Pros}} & \multicolumn{1}{p{1.5in}}{\textbf{Cons}} & \textbf{Size} & \textbf{Cost} \\
\midrule
Reinforced concrete & \item Strong \item Secure & \item Prone to leaks \item Relatively expensive to install \item Heavy  & 100,000 gal & \$299,400 \\ Steel & \item Strong \item Secure & \item Relatively expensive to install \item Heavy \item Require painting to prevent rusting & 100,000 gal & \$130,100  \\

Polypropylene & \item Easy to install \item Mobile \item Inexpensive \item Prefabricated  & \item Relatively insecure \item Max size available 10,000 gal  & 10,000 gal & \$5,000 \\ Wood & \item Easy to install \item Mobile \item Cheap to install & \item Prone to rot \item Must remain full once constructed & 100,000 gal & \$86,300\\
\bottomrule
\end{tabular}%
}
\end{table}

\end{document}

-
thank you. What's the difference between \textbf{} and {\bf }? –  Usagi Feb 11 '11 at 22:20
@Usagi: \bf is outdated LaTeX2.09 syntax. It doesn't stack, e.g. {\bf\it Text} does not do bold italic text, but only italic, because the last command overwrites the earlier ones. However, \textbf{\textif{Text}} works. There are also \bfseries and \itshape as well as \ttfamily if you do not want a macro which takes an argument. –  Martin Scharrer Feb 11 '11 at 22:26
Thanks for the help! –  Usagi Feb 13 '11 at 20:58