In Re the Marriage of: Stacey Ann Marcino, petitioner, Respondent, vs. Joseph William Marcino, Appellant.

may not be cited except as provided by

Minn. Stat. § 480 A. 08, subd. 3 (1996).

 STATE OF MINNESOTA

 IN COURT OF APPEALS

 C7-98-869

In Re the Marriage of:

Stacey Ann Marcino, petitioner,

Respondent,

vs.

Joseph William Marcino,

Appellant.

 Filed November 17, 1998

 Affirmed in part and remanded;

motion to strike granted;

 motion for attorney fees denied

 Thoreen, Judge[*]

Washington County District Court

File No. FX-96-1442

John R. Hill, Larkin, Hoffman, Daly & Lindgren, Ltd., 1500 Norwest Financial Center, 7900 Xerxes Avenue South, Bloomington, MN 55431-1194 (for respondent)

J. Peter Wolf, Shelly D. Rohr, Wolf & Rohr, P.A., 960 Norwest Tower, 55 East Fifth Street, St. Paul, MN 55101 (for appellant)

Considered and decided by Lansing, Presiding Judge, Anderson, Judge, and Thoreen, Judge.

 U N P U B L I S H E D O P I N I O N

 THOREEN, Judge

Appellant challenges the district court's award of joint custody of the parties' children, level of child support, and failure to rule on daycare and child support arrearages. Respondent notices review of the access schedule and the allocation of daycare costs. Because we find that the district court did not abuse its discretion, we affirm on all issues except daycare and child support arrearages, which we remand for further proceedings.

 FACTS

Appellant Joseph Marcino and respondent Stacey Marcino had two children during their marriage; C.M., born April 9, 1990, and K.M., born April 23, 1992. The parties separated on October 1, 1995, when respondent moved out of the home and left the children with appellant.

At the initial hearing, the parties agreed to temporary primary physical custody with appellant. The court ordered respondent to be responsible for daycare expenses and granted her visitation for a total of 156 overnight visits a year.

Experts differed in their custody recommendations. The county domestic relations counselor recommended sole physical custody with appellant and a visitation schedule for respondent that resulted in approximately 130 regular overnight visits per year. A private psychologist recommended joint physical custody and an access schedule for respondent that resulted in approximately 157 regular overnight visits.

Following trial, the district court awarded joint legal and physical custody, set child support, and resolved other financial questions. The court set an access schedule for respondent that resulted in 117 overnight visits per year. On appeal, appellant seeks sole physical custody, child support based on sole physical custody, and an order for respondent to pay child support and daycare arrears of $1,915.44. Respondent seeks modification of her access schedule and her daycare obligations.

 D E C I S I O N

 1. Custody

  (a) Joint Physical Custody

A district court has broad discretion to provide for the custody of the parties' children. Rutten v. Rutten, 347 N.W.2d 47, 50 (Minn. 1984). An appellate court will not reverse a custody determination unless the district court abused its discretion by making findings unsupported by the evidence or by improperly applying the law. Pikula v. Pikula, 374 N.W.2d 705, 710 (Minn. 1985). A district court's findings will be sustained unless they are clearly erroneous. Id.

Joint physical custody exists when "the routine daily care and control and the residence of the child is structured between the parties." Minn. Stat. § 518.003, subd. 3(d) (1996). Joint physical custody is not a preferred arrangement. Kaehler v. Kaehler, 219 Minn. 536, 539, 18 N.W.2d 312, 314 (1945), cited in Peterson v. Peterson, 393 N.W.2d 503, 506 (Minn. App. 1986); see also Heard v. Heard, 353 N.W.2d 157, 162 (Minn. App. 1984). Indeed, a grant of joint physical custody will be appropriate only in exceptional cases. Brauer v. Brauer, 384 N.W.2d 595, 598 (Minn. App. 1986).

To award joint physical custody, the district court must address the factors in Minn. Stat. § 518.17, subd. 2 (1996), but it need not make a specific finding for each one. See Berthiaume v. Berthiaume, 368 N.W.2d 328, 332 (Minn. App. 1985). "It is sufficient if the findings as a whole reflect that the [district] court has taken the relevant statutory factors into consideration in reaching its decision." Id.

This court has consistently held that the essential factor on which joint physical custody depends is the parties' ability to cooperate. See, e.g., Wopata v. Wopata, 498 N.W.2d 478, 482-84 (Minn. App. 1993) (joint physical custody not awarded to parties equally qualified to raise children but not qualified to raise them jointly); Veit v.Veit, 413 N.W.2d 601, 605 (Minn. App. 1987) (joint physical custody appropriate where parties cooperated for three years after separation); Greenlaw v. Greenlaw, 396 N.W.2d 68, 74 (Minn. App. 1986) (joint physical custody improper where parents unable to communicate effectively); Berthiaume, 368 N.W.2d at 332-33 (joint physical custody upheld where parents shared same parenting philosophies and cooperated, despite their inability to cooperate during dissolution); Heard, 353 N.W.2d at 162 (joint physical custody improper where there was no cooperation and parties could not resolve their own disputes).

The district court found that the parties have similar values regarding their children but are experiencing temporary difficulty cooperating due to the dissolution process. Appellant believes that he and respondent cannot cooperate, while respondent believes that they can. The experts disagree as to the parties' ability to cooperate. Because there is evidence to support the district court's finding that the parties can cooperate, and because a custody award is within the court's discretion, we affirm the award of joint physical custody.

  (b) Access Schedule

In determining custody, a court has discretion to accept or reject a custody study's recommendation. Rutanen v. Olson, 475 N.W.2d 100, 104 (Minn. App. 1991). Where a district court does not follow a study's recommendation and makes no findings as to why it rejected that recommendation, but does make detailed findings which reflect a complete analysis of the same factors that the study addressed, there is no abuse of discretion. Id.

Respondent claims that the district court abused its discretion by creating its own access schedule rather than accepting one of the schedules recommended by the parties or the experts. Citing Rutanen, respondent claims that this is an abuse of discretion because the district court's findings do not explain how it arrived at an access schedule. Respondent, however, misstates Rutanen which stands for the proposition that the court need not make findings on the studies themselves when it makes findings consistent with those studies. Id. Here, the district court made detailed findings regarding the best interests of the children. We therefore affirm the district court's access schedule.

 2. Child Support

  (a) Level of Child Support

In general, the district court has broad discretion to provide for the support of the parties' children. Rutten, 347 N.W.2d at 50. The court will not reverse the district court's decision on child support unless that decision was clearly erroneous. Id. at 51. In joint physical custody cases, the court must require each parent to pay his or her child support guidelines amount for time when the other parent has custody. Valento v. Valento, 385 N.W.2d 860, 862 (Minn. App. 1986), review denied (Minn. June 30, 1986).

The district court followed Valento and required each party to pay the guidelines amount when the other party has custody. Appellant argues that because he has the children 70% of the time, he in essence has sole physical custody and should not be required to pay child support. Appellant offers no legal support for this theory, which runs counter to Minnesota law as set forth in Valento. We affirm the award of child support.

  (b) Daycare and Child Support Arrearages

At trial, appellant submitted evidence indicating respondent owed arrearages, which the original findings and judgment did not address. In his motion for amended findings of fact and conclusions of law, appellant asked for a conclusion that "arrearages in child support owing by respondent to petitioner * * * of $1915.44 * * * shall not merge with Judgment and Decree herein." In its order amending judgment, the district court did not address the issue except by its denial of "all other motions."

Minn. R. Civ. P. 52.01 requires a court to make findings of fact and conclusions of law when trying a case without a jury. Because appellant was entitled to findings relating to arrearages, we remand on this issue.[1]

  (c) Allocation of Daycare Costs

Respondent argues that the district court abused its discretion by not assigning each party a percentage of the costs of daycare rather than a fixed dollar amount per month. Respondent argues a percentage of the costs is preferable because daycare needs vary on a monthly basis. Respondent has not presented any evidence of this variance.

Respondent cites no statutes or case law to support her argument. As the setting of child support is a matter within the district court's discretion, we affirm the district court.

 3. Motions

  (a) Motion to Strike

Minn. R. Civ. App. P. 110.01 states that the "papers filed in the trial court, the exhibits, and the transcript of the proceedings, if any, shall constitute the record on appeal in all cases." An appellate court may not base its decision on matters outside of the record on appeal; matters not part of the record must be stricken. Mitterhauser v. Mitterhauser, 399 N.W.2d 664, 667 (Minn. App. 1987).

Respondent argues that the court should strike from appellant's appendix a letter from the guardian ad litem to the district court and a letter from the assistant guardian ad litem program manager to the court, and all references to these letters in appellant's brief from the record on appeal. These letters are not part of the district court's file and the parties did not offer them into evidence. We therefore grant respondent's motion to strike.

  (b) Attorney Fees

Respondent requests an award of attorney fees for bringing the motion to strike. A court may award attorney fees in a marriage dissolution proceeding where the court, in its discretion, has found that a party has unreasonably contributed to the length or expense of the proceeding. Minn. Stat. § 518.14, subd. 1 (1996). Awarding attorney fees is within the broad discretion of the appellate court. Case v. Case, 516 N.W.2d 570, 574 (Minn. App. 1994).

Appellant violated Minn. R. Civ. App. P. 110.01. However, as the letters were mailed to the district court, there is a good faith argument that they were part of the record on appeal. We deny the motion for attorney fees.

  Affirmed in part and remanded; motion to strike granted; motion for attorney fees denied.

[*]Retired judge of the district court, serving as judge of the Minnesota Court of Appeals by appointment pursuant to Minn. Const. art. VI, § 10.